phase multipath estimation for global positioning system (gps

380
Phase Multipath Estimation for Global Positioning System (GPS) Using Signal-to-Noise-Ratio (SNR) Data by Francesca Scir6 Scappuzzo B.S. and M.Eng., Summa Cum Laude , Electrical Engineering University of Catania, 1989 Submitted to the Department of Earth, Atmospheric, and Planetary Sciences in Partial Fulfillment of the Requirements for the Degree of Master of Science in Earth and Planetary Sciences at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY May 1997 @ 1997 Massachusetts Institute of Technology All rights reserved. Signature of Author Department of Earth, Atmospher(icand Planetary Sciences May, 1997 Certified by Thomas A. Herring Associate Professor of Geophysics Thesis Supervisor Accepted by ARCHIVES Thomas H. Jordan Department Head , -tj , 8 '.-,.7 AV(-

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Phase Multipath Estimation for Global Positioning System (GPS)

Using Signal-to-Noise-Ratio (SNR) Data

byFrancesca Scir6 Scappuzzo

B.S. and M.Eng., Summa Cum Laude , Electrical EngineeringUniversity of Catania, 1989

Submitted to the Department ofEarth, Atmospheric, and Planetary Sciences

in Partial Fulfillment of the Requirements for the Degree of

Master of Science in Earth and Planetary Sciences

at theMASSACHUSETTS INSTITUTE OF TECHNOLOGY

May 1997

@ 1997 Massachusetts Institute of TechnologyAll rights reserved.

Signature of AuthorDepartment of Earth, Atmospher(icand Planetary Sciences

May, 1997

Certified byThomas A. Herring

Associate Professor of GeophysicsThesis Supervisor

Accepted by

ARCHIVES Thomas H. JordanDepartment Head

, -tj , 8 '.-,.7AV(-

This thesis is dedicated to

Prof. Sebastiano BarbarinoAssociate Professor of Electromagnetics

University of Catania, Italy

... perche' il Suo amore per lo studio e per la scienza,la Sua encomiabile dedizione all'insegnamento e

la Sua grande umanita'

siano da esempio ai Suoi studenti e colleghi

ed ispirino le generazioni a venire ...

Phase Multipath Estimation for Global Positioning System

(GPS) Using Signal-to-Noise-Ratio (SNR) Data

byFrancesca Scire Scappuzzo

Submitted to the Department of Earth, Atmospheric, and Planetary Sciences

in Partial Fulfillment of the Requirements for the Degree of

Master of Science in Earth and Planetary Sciences

Abstract

A method for the estimation of GPS multipath phase error is proposed. Becausethe Signal-to-Noise-Ratio (SNR) of the GPS measurements is strictly related to themultipath phase error, the algorithm implemented manipulates the SNR of thereceived GPS signal itself to perform the estimation. No additional informationabout the geometry of the surroundings of the receiving station or the weatherconditions at the time of acquisition are needed. The scattering phenomenon isgenerally due to the composition of several single multipath contributions, each onecharacterized by a specific frequency. The algorithm takes advantage of thisproperty to decompose the variations of the SNR into individual components in aniterative procedure. The contributions due to each frequency are then superimposedto obtain the total multipath phase error.

The algorithm was applied to several data sets affected by strong multipath to testthe performance of the method. Spectral and statistical analyses were performed tocompare the observed phase residual obtained from the GPS measurements and theestimated multipath phase error retrieved by the algorithm.

In most of the cases analyzed, a broad-band coherence function between theobserved phase error and the estimated multipath phase error was found in presenceof strong multipath. This suggests that the effects of multiple reflectors are correctlyretrieved by the proposed algorithm.

The set of data which show the highest coherence have multipath frequenciesbetween 0.001 and 0.01 Hz. Therefore, the estimation algorithm presents goodperformances when the reflectors are located at a distance between 5.50 m and 55.0m from the receiving antenna, for an elevation angle of about 10' and a rate of changeof the elevation angle of 0.1 mrad/sec. The high coherence is confirmed by thestatistical analysis, which shows a significant decrease of the RMS of the phaseresidual after the multipath correction.

At lower frequencies it was found that the performance of the algorithm dependson the receiver type, the antenna gain and the weather conditions.

Thesis supervisor: Thomas A. HerringTitle: Associate Professor of Geophysics

Contents

Introduction 9i.1 Objectives ..................................................

1.2 Outline ..................................................... II

2 Multipath Modeling in phasor space. Relationship between

Multipath Phase Error and SNR 132.1 Introduction ................................................. 13

2.2 Multipath representation ...................................... 52.2.1 Multipath Modeling in the Phasor Space .................. . 52.2.2 Relationship between the signal strength and the multipath

phase error ........................................... 18

2.2.3 The SNR and the measured signal strength, Ac ........... 212.2.4 Multipath frequency ................................... 222.2.5 Influence of the Reflection coefficient on the multipath

phase error ........................................... 24

2.2.6 Antenna Gain contribution to the Signal strength ........... 312.3 GPS receivers in presence of multipath ......................... 35

2.3.1 GPS receivers ......................................... 352.3.2 The DLL and PLL in the presence of multipath ............ 362.3.3 L2 signal processing in the presence of AS (Anti-spoofing) .... 37

3 Description of the algorithm for the Multipath Phase Error

Estimation from the SNR data 39

3.1 Introduction ................................................ 39

3.2 Errors in the GPS Phase Measurements ....................... 40

3.3 Multipath Phase Error Estimation Algorithm ..................... 42

3.3.I Antenna Gain removal .................................. 42

3.3.2 Data Segment Selection ................................. 46

3.3.3 Spectral Decomposition of the SNR ...................... 46

4 Statistical and Spectral Analysis of estimated and observedGPS phase errors

4.1 Introduction ................................................

4.2 Data Preprocessing .. .....................................

4.3 Spectral Analysis ........................................

4.3.1 Multipath Frequency ...............................

4.3.2 Power Spectral Density .............................

4-3.3 Auto Correlation and Cross Correlation ...................

4.3.4 Auto and Cross Spectral Density Function .................

5.3.5 Coherence Function ..................................4-4 Statistical Analysis of GPS Phase Residual ......................

Applying the method ofmultipath estimation to GPS data

5.1 Introduction ..........................................

5.2 Description of the GPS stations and the data sets analyzed .........

5.2.1 The Tien-Shan data ....................................5.2.2 The LIGO data .. ....................................5.2.3 The IAP data ........................................

5.3 Multipath Estimation and Results of Spectral Analysis ............

5.3.1 KKAU and MANA ..................................5.3.2 Station 0036 and 0028 (TRIMBLE 4oooSSE) ..............

5.3.3 COSE and GS29 ....................................

5.4 Multipath Estimation and Results of Statistical Analysis ............

6 Conclusions

53.53-54.55.55.55

.56

.58

.59

.60

.63

.64.64

.65

.65

.67

.67

.71

.74

.77

79

REFERENCES .................................................... 83

APPENDICES .................................................... 90

A. Plots of spectral analysis

B. Tables of statistical analysis

C. Matlab Algorithms

Chapter 1

Introduction

Over the last decade the Global Positioning System (GPS) has become a very

useful tool for several scientific and civilian applications, playing a leading role in

geodynamic studies, from a local to a global scale. High accuracy GPS is being

extensively used in large scale dynamics of the Earth, such as plate tectonics, Earth's

rotation studies, sea-level change, post-glacial rebound, tidal effect and sea-surface

topography.The extensive utilization of GPS in geosciences is mainly due to the recent

significant improvements of the techniques involved in high-accuracy GPS

positioning. The relatively low costs of post processing software and new GPS

receivers and their availability and portability during field work, make the GPS a very

convenient and useful instrument. The international collaboration in the GPS

scientific community is also sensibly contributing to such a wide diffusion of the

system.

However, even though research and technology on high accuracy GPS positioning

have rapidly developed, there is still a broad range of critical issues that scientists and

engineers need to exploit. Most of the new questions arise from the fact that the

fields of application and the accuracy required today for positioning instruments,

have greatly overcome the purposes for which GPS was originally designed,

producing a series of new challenging riddles.

One of the main problems to be faced when performing high-precision GPS

measurements is the error in positioning due to the occurrence of multipath. This

phenomenon is caused by the interference of multiple reflections with the direct

EM signal transmitted by the satellite, and represents a considerable source of error

in the GPS carrier phase observations (fig. 1.1).

The level and characteristics of the noise deriving from multipath depends upon

the geometry of the surrounding of the receiving antenna (presence of buildings,

trees, towers, and the mount itself), the reflectivity of nearby reflectors, the elevation

angle of the satellite at the time of acquisition, and other parameters which might

sensibly change with weather conditions and time.

GPS satellite

rface

GPS receiver

Fig. 1.1: GPS multipath phenomenon

Due to the variability of the parameters involved, it is very difficult or evenimpossible to predict multipath with sufficient accuracy using a deterministicapproach such as electromagnetic modeling or analog techniques.

1.1 Objectives

The objective of the study presented in this thesis is to estimate the multipathphase error from the SNR (Signal-to-Noise-Ratio) data, without using any a prioriinformation about the location of the receiving station, the weather conditions andthe geometry of the surroundings. This method manipulates the SNR of the

received signal, which in GPS data processing is usually only used as an indicator ofthe data reliability and is not used for the positioning itself.

In order to test the performance of the estimation algorithm for different sites and

different GPS receiver types (Ashtech Z-12, Trimble SSE and SSI, and Turbo-Rogue SNR8000), the method was applied to a large number of data sets, chosen forthe strong multipath in the phase error measurements.

1.2 Outline

In chapter 2 a mathematical representation of the multipath phenomenon is

derived. The dependency of the multipath phase error on the SNR, the antenna

gain, the multipath frequency and the reflection coefficient of the reflecting surface

is discussed.

After a brief introduction on the basic operation of GPS receivers, chapter 3

focuses on how a GPS signal corrupted by multipath is processed by differentreceivers.

The algorithm for the estimation of the multipath phase error from the SNR data

is described and discussed in chapter 4.

In order to test how well the estimated multipath phase error matches the phase

error observed in the GPS measurements, statistical and spectral analyses were

performed. The theory of these analyses is presented in chapter 5.

The estimation algorithm was applied to several data sets affected by significant

multipath effects. Its performance was studied comparing the results obtained in

the different cases. The results of this analysis are discussed in chapter 6 and the

conclusions are drawn in chapter 7.

The plots relevant to the estimation and spectral analysis of the 42 data sets

studied are collected in appendix A. In appendix B, the tables containing the

results of the statistical analysis are shown. The matlab programs implemented for

the analysis can be found in appendix C.

Chapter 2

Multipath Modeling in phasor space.

Relationship between Multipath

Phase Error and SNR

2.1 Introduction

The correction of GPS multipath phase errors is one method of improving theaccuracy of GPS measurements. In literature several approaches for GPS multipathcorrection can be found. Hajj (1990) developed an algorithm to produce maps of the

multipath for a given environment around the receiving antenna. Unfortunately,multipath errors are very sensitive to parameters such as the geometry or the

reflection coefficient of nearby reflectors which strongly depend on the particular

weather condition and season. This limits the efficiency of this method in

predicting the multipath effects with time.

An easy solution to the multipath problem consists in selecting a proper site, far

from possible reflectors. However in many applications it is not possible to choose

the site for the GPS positioning. Other ways to minimize multipath consist in the

design of antennas which reduce back-plane gain. Receivers manufacturers are

trying to correct multipath using particular selections of the cross-correlation

function. A branch of research on GPS multipath, is now oriented toward the

analysis of the data itself for the error estimation in post-processing mode

(Georgeadu and Kleusberg, 1988). One new promising method is to compute the

multipath error by using the SNR, as in Axelrad et al., (1994).

The circumstances in which the measurements are acquired are usually recorded

on the log sheets of the GPS measurements, which report the geometry of the site,the weather conditions during the data acquisition, etc. But to gather the correct

information about the GPS receiver surroundings and relevant measurements can be

extremely difficult and inefficient. The possibility to correct for multipath

contribution to the phase error without a priori information is particularly important

for applications that require networks of GPS stations distributed over large areas on

the globe, such as geosciences.

The multipath phase error estimation algorithm proposed in this thesis makes use

of the SNR of the data itself, without the need for additional information about the

geometry and conditions of the surrounding of the receiving antenna. The methodfor the estimation of 50, is based on the spectral analysis of the SNR information

provided by the GPS receiver. We assume that the multipath effects are due to

multiple reflectors, which will each have a particular frequency. Through spectral

decomposition of the SNR we can isolate the contributions of each reflector.

Inverting for the phase error of all the single contributions and superimposing the

results together, we obtain the total multipath correction (total multipath phase error).

This chapter is devoted to the definition of the theoretical model of the multipath

phenomenon used in the multipath phase error estimation algorithm. The importantrelationship between the multipath phase error to be estimated , 80, and the SNR

data, used as input of the estimation algorithm, is discussed in section 2.2.2. The

dependency of the signal strength (A) and the multipath phase error (&0) on the

phase of the multipath signal, on the multipath frequency and on the reflection

coefficient of the reflecting surface is derived in sections 2.2.4 and 2.2.5. The

influence of the antenna gain on the signal strength is shown in sections 2.2.6.

2.2 Multipath representation

2.2.1 Multipath Modeling in the Phasor Space

In this section the mathematical model of the multipath phase error used for the

estimation algorithm is derived.The multipath phase error, 80D, is defined as the angle between the direct signal,

Sd(t), and the total received signal, Sc(t), which is the composition of the direct signal

and the multipath signal, Sm(t). The signals can be written as:

i(Co't + Od)Sd (t)= Ad (t).e [2.1]

Sm (t) = Am (t).e 't [2.2]

i t't+mi

= A ei( t' t + d ) (t . [2.3]Sc (t) = Ac (t) -ei( O = Ad (t) + mi [2.3

where:Ad = Amplitude of the direct signal

Ami = Amplitude of the i-th multipath contribution

kA= Amplitude of the total measured signal

Od = Phase of the direct GPS signal.4mi= Phase of the multipath signal due to the i-th reflector.

OC = Phase of the total measured GPS signal.o = 2 7 f and f is the carrier frequency (LI or Lz)

In figure 2.1 the total signal measured by the receiver, the direct signal and the

signal due to the composition of several multipath reflections are shown in the

phasor space.

Figure 2.1: Phasor diagram of the GPS signal. 80 is the multipath phase error

in presence of a single reflector. It depends on the amplitude

(Am=Rf Ad) and phase (Om=Od+fmt) of the multipath phasor.

In the phasor space the signals of fig. 2.1 can be written as:

A = Adl ei d

AmmAm = Ami. ie

i-A = AcI e e

Om, = Od + Pi = d + (fm, t)

[2.4]

[2.5]

[2.6]

im

where:i = Phase of the i-th multipath signal with respect to the direct GPS

signal

fni = Multipath frequency relevant to the i-th contribution, such that

Pi =fmi t +0oi

0oi = Phase of the i-th multipath signal with respect to the direct GPS

signal at the initial time t=0.80- Total multipath Phase Error

Rfi= Reflection coefficient for the i-th reflector. IAmil = Rf IAdl.

The composite signal is given by:

c = d +Ami = Ad .ed + + R Ade( d + i) [2.7]

The multipath phase error depends on the amplitude of the multipath signal

and its phase. Because 3 changes with time as a function of the multipath frequency

fm, the multipath phasor spins around the tip of the direct signal, producing positive

and negative values of the phase error 80.

If we rotate the diagram of figure 2.1 as in figure 2.2, so that 4d -0 and Ad is along

the Real axis, the total strength of the received signal and the phase error can be

written as:

lAc = Ad (1 + Rfifi cosi) 2 +(.Ri, sini )2 [2.8]V+ýi [28

[2.9],,

tcp =

Im(Ac

Figure 2.2: Phasor diagram 2.1 for Od =0 and Ad real.

2.2.2 Relationship between the signal strength and the

multipath phase error.

The amplitude of the composite signal Ac is related to the total phase error, 80through the angle P3, phase of the multipath vector Am with respect the direct signalAd (fig. 2.1, formulas [2.8] and [2.9]).

To describe the phenomenon, we consider the simple case of a single reflector(i=1). (The same theory is applicable to multiple reflections, considering thesuperposition of the multipath contribution).

Re

Because the multipath signal rotates around the tip of the direct signal , withfrequency fim, the amplitude of Ac oscillates between a maximum value Ad +Am and a

minimum value, Ad -Am. The change in amplitude of Ac due to the rotation of Am

can be easily deduced from 2.3. Ac is plotted as function of time for different values

of 1. Every time A, presents a maximum ( for 3=0' ) or a minimum ( for 1=180" ), themultipath phase error is zero. The maximum phase error occurs for P=90" and

1=270'. (see fig. 2.1 and formula [2.9] ).In table 2.1 the values of A, and 6Q as functions of P are summarized . It is

important to notice that Ac can assume the same amplitude for different values of 1(for example for P=90" and 1=270'). This produces an uncertainty in thedetermination of the sign of 86, which represent a very critical problem in the

multipath phase error estimation algorithm.

Ac =SNR

t

=0° 13=900 1-1800

Figure 2.3: Variation of Ac with the time, as function of the angle 3.

/= Phase error

A =A +Ac d

(Max SNR)

0 = f t = 900 =* Phase error

SNR

+ = tan - 1 [m (Max 8I)

A = A 2 + A 2c d m

= f.t = 180 0 = Phase error

Ac = Ad - A mc d m (Min SNR)

/ = fQt = 2700 = Phase error

SNR

- 31 = -tan - 1 (Min &0)AA

A = Ad 2 +A 2c d m

Table 2.1 : Signal strength, Ac and multipath phase error, 80, as functions of 3.In section 2.2.3 it is shown that Ac and the Signal-to Noise-Ratio (SNR)

actually represent the same quantity in the GPS receiver processing.The relationship between the SNR and 80, is crucial for the phase

error estimation algorithm presented in chapter 4.

SNR

50 = 0

SNR

,= fl t = 00 30 = 00

2.2.3 The SNR and the measured signal strength, Ac

In table 2.1 the amplitude of the received signal is assumed to be equal to thevalue of the SNR computed in the receiver. This section shows why Ac and SNR in

the receiver represent the same quantity.

From formula [2.3], considering the PRN code function, the signal received bythe GPS ground antenna can be expressed as:

-4("t+ d) i(j -t+ mi)Sc (t) = ad(t) -P(t) ei + .Ami (t) -P(t + 8) e [2.10]

where:

P(t) is the PRN code (±1)8- multipath time delay

The signal internally generated in the receiver is given by:

S (t) = P(t + ). -e( t + ) [2.11]

where:

oo = Local Oscillator frequency

, = Tracking error of the Delay Lock Loop (DLL)

0 = Tracking error of the Phase Lock Loop (PLL)

In the receiver the GPS signal [2.10] is down-converted, cross-correlated with the

signal internally generated, and filtered. The result of this sequence of operations

gives the equations [2.4], [2.5] , and [2.6] introduced at the beginning of this

chapter.

In particular, A, represents the normalized average correlation coefficient, which is

the ratio signal/noise. In formulas:

= normalized corr. coeff. = SNR

where:SNR = Signal Strength [2.13]

Noise

However, the precise normalization used in the receiver is not always the same, butdepends on the particular manufacturer. We can assume that the values of thecorrelation coefficient are normalized by the expected correlation coefficient when

only noise is present.It follows that the SNR is equivalent to the signal strength of the total composite

signal, Ac. Therefore, all the properties we found for Ac are valid also for the SNR.In table 2.1 the values of the SNR and 601 as function of P were summarized.

2.2.4 Multipath frequency

The multipath phase error depends on the multipath frequency. The implicationsof this dependency are very important in the spectral analysis performed for themultipath phase error estimation algorithm described in the following sections.

As already shown in section 2.2.1, the phase of the i-th multipath signal Ami is

given by [2.5] :Om, = d +f [2.14]

wherefi = i, " t [2.15]

Substituting 2.15 in 2.9 we obtain an expression of 8(1 as a function of fm:

(f )= tan-1 +Rfco t) [2.16]m+R -cos(fmt)

AC = SC (t) -SLO (t)) [2.12]

The frequency of the i-th multipath error depends on the carrier frequency, the

distance of the i-th reflector and the receiving antenna, the rapidity of the change in

elevation angle of the satellite and the elevation angle.

For an horizontal reflector at distance hi below the antenna, the multipath

frequency is (Leich, 1995):

i, = -. sin y- [2.17]

where:

h = Distance between the antenna phase center and the reflector

S= Wavelength

Nr = Zenith angle = (90' - Elevation angle)

One of the consequences of equations [2.16] and [2.17] is that 80 varies with time

due to changes of the elevation angle, as the satellites rises or sets.

Moreover, the multipath phase error, 80, presents a particular frequency

component fmi for each reflector located at a certain height below hi from the

receiving antennas. From [2.8] and [2.9] we can deduce that Ac (=SNR) and 8o

present the same spectral content, being both functions of 13=fmt.

Therefore, the multipath phase error 50i due to a particular reflector can be

identified by the spectral analysis of the total signal strength Ac (SNR).

The method for the estimation of the total composite 8I, is based on the spectral

analysis of the SNR information provided by the GPS receiver. We assume that the

multipath effects are due to multiple reflectors, which will each have their own

frequency. Through spectral decomposition of the SNR we can isolate the

contributions of each reflector. Inverting for the phase error of all the single

contribution and adding them together, we obtain the total multipath correction, as it

will be shown in more detail in chapter 4.

2.2.5 Influence of the Reflection coefficient on the multipath

phase error

The multipath phase error 80i is a function of the Reflection Coefficient Rf, as

shown in formula [2.9]. The reflection coefficient depends on the electromagneticcharacteristics of the reflecting surface, such as permittivity (e), permeability (g), and

conductivity (d). It depends also on the frequency of the electromagnetic signal and

the elevation angle of the satellite 0.In this section we derive the expression of the reflection coefficient Rf for one

single reflector as a function of E, gt, and a, and discuss how these electromagnetic

properties of the reflector influence the multipath phase error.The geometry of our problem is shown in figure 2.4, where Einc is the incident

electromagnetic wave transmitted by the GPS satellite, Et is the EM wave refracted

into the material and Er is the EM wave reflected by the surface.

Ci.

z

Figure 2.4: Electromagnetic plane waves propagating in medium 1 (air) and

medium 2 (reflector).

I A--J:. & A--J: . -

The incident electromagnetic plane wave emitted by the satellite, propagatingin medium 1 toward medium 2, can be written as:

E = Eo e- i(t- •.r ) [2.18]

The plane wave reflected by the surface, propagating in medium 1 away frommedium 2, can be written as:

Er = Ero .e- i(• - v) [2.19]

where :

k = Wave number

F= /3+ia [2.20]

k2 = ie(-ieW) = o 2E + iaUT

Substituting k( [2.20]) in [2.18] and [2.19] we obtain:

Ei, = Eo -(e-a-r, ). e-i('r, [2.21,)

Er = Ero (e-a.r, ). e-i(Otpr,)

where:a = Attenuation Coefficient (Np/m)

p = Propagation Coefficient (rad/m)

e-(ar) = Attenuation factor

e- (r) = Propagation factor

Solving [2.20] for a and 0, the Attenuation Coefficient and the Propagation

Coefficient can be written as (Balanis, 1989):

S= o 1+ 22 1 [2.22]2 E2)2

0_ a2 + [2.23]

The term e - (ar) represents the attenuation of the electromagnetic wave in the

material, and the exponential e -j(r) represents the propagation term. Note that for

air (medium 1 where the GPS signal propagates), a 1= 0, and therefore e -(ar) s 1.

The electric fields of the incident and reflected wave can be decomposed in a

component perpendicular to the plane of incidence (horizontal polarization) and a

component parallel to the plane of incidence (vertical polarization). In formulas:

Horizontal Polarization:

-h [Eh e-i',(xsinO,+zcosO,)[2.24]

Eh h E -i,(xsin,-zcos)[2.2

Vertical Polarization:

-. = [E . e-iPj(xsin°j+zCs cos] O- ,sin 0) 2.25

Er = [E',0 e-iP,(xsin,-zcos,)] (ycos Or + isin Or)

where:

0i = Incidence angle

Or = Reflection angle

The Fresnel Reflection Coefficient for the horizontal (perpendicular)

polarization is given by:

Erh =2 COS Oi - 071 COS 8 t

EihN, 772 COS Oi 771 COS Ot

cos 8- 1172

cos ei + .1072

[2.26]

The Fresnel Reflection Coefficient for the vertical (parallel) polarization is given

by:

S= Er -171 cOS 8i + 72 COS OtEi 71 cos Oi + 772 COS Ot

-cos Oi + _2171

cos 90 + 02

where:

Ot = Refraction angle

= Intrinsic impedance of the medium.

The angles of Incidence, Reflection and Refraction, of fig. 2.4 are related by

the Snell's laws:

O0 = Oik1 sin Oi = k2 sin 8,

Snell's law of reflection

Snell's law of refraction

[2.28][2.29]

The Intrinsic Impedance of a medium is given by:

for dielectric materials

{ iouM for conductive materials0'+i oe

[2.30]

In our case, the medium 1, where the incident and reflected signal propagate, isair. For air the intrinsic impedance can be considered as the one for dielectricmaterials.

[2.27]

EH1=-=H

Depending on the electromagnetic characteristics of the reflector, we can

distinguish 3 cases, which represent 3 different categories of materials.

Case I: Good Dielectrics

If the reflector (medium 2) is a good dielectric at the frequency of the GPS

signals (Microwaves) we obtain:

'222 2 << 1E2 02

=71 = •1 -72 2

and Rf =f

-cos ei - cIL cos o~n_ •E2 E

C2 1

-I COS 0 + 12COS +62 re,2

Scos o,

Case II: Quasi-conductors

If he reflector is a quasi-conductor at the frequency of the GPS signals,it follows that:

and Rf = <

iW o s2 C/ t cos7" + i0E2 OS

iRh 2 2 osO

Scos Oi + cos 82 2___ /1

-cos O + i92 cos ORV= a 2 + i(82

cosBi + i cos O,Ei "2 + i082

2

E2 2 1

,22(02

-1i =

772a 2 + itoE2

cos i +R

Inh =

In this case the reflector is not a good dielectric, nor a good conductor, havinginter medium characteristics. The reflection coefficients (horizontal and vertical)can be determined using the general formulas [2.26] and [2.27] , respectively.

Case III: Good Conductors

If the reflector is a good conductor at the frequency of the GPS signals,considering the approximation of formulas [2.26] and [2.27] we obtain:

>> 1 2 >16220)2 72

rRh -1>> 1 cos9. and Rf =

R, +1

Thus, for a very good conductor the magnitude of the reflection coefficients forhorizontal (perpendicular) and vertical (paralleD polarization approaches unity. Thisimplies that Am Ad and, therefore, the multipath phase error, 80, is very high.

It can be noticed that for a very good conductor the reflection coefficientsbecome essentially independent of the angle of incidence.

In fig. 2.5 a summary of the electromagnetic properties of some materials atdifferent frequencies is shown. (Kraus, 1992).

At microwave frequencies (at which GPS operates) sea water and wet rural groundare quasi-conductive, while dry ground and urban ground are in the dielectric region.

It is interesting to notice that because wet ground is more conductive than dryground, it reflects the GPS signal better, producing a stronger multipath, even if thegeometry of the antenna surroundings is maintained constant.

In general fresh water has a o =10-3 mho/m while salt water has a much higherconductivity a = 4.0 mho/m. Depending on the soil conditions (i.e. how much salt isin the soil the ground presents different conductivity after rain.

Quartz (which is a good approximation to sandy soil) has a dielectric constant of

4 and, therefore, the reflection coefficients persent values between 0.3 and 0.6,depending on the incidence angle. At low elevations an increase of moisture

content might increase the reflection coefficient of 60%, so that the reflectioncoefficient is almost unity. (R 1).

This example suggests that the weather conditions might influence theperformance of GPS measurements, because of the different multipath environmentthey can produce.

M = 6

5

4

3

2

1

0

-1

-2

-3

-4

-5

.V = 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17Frequency = 10v Hz

Fig. 2.5 Ratio ao/w as a function of frequency for some common media.

At Microwave frequencies the most of the media shown are in thequasi-conductive region (urban ground, rural ground, sea water), with theexception of copper, which, being a metal, is a very good conductor evenat higher frequencies, up to the Visible spectra. (Kraus, 1992)

-4

-5

2.2.6 Antenna Gain contribution to the Signal strength

In formula [2.8], Ac is described as a function of Ad ,Rf and P. We already

discussed its dependency on Rf and P. To complete this theoretical analysis of 80

and Ac we need to study how the amplitude of the direct signal, Ad is influenced by

Ac. The direct signal sent by the transmitting antenna, Ad, is a function of the GPS

satellite antenna pattern, as will be discussed in section [2.2.6.1]. The total signal

measured by the receiver, Ac, depends on the receiving antenna pattern (section

[2.2.6.2] ).

22.6.1 GPS Transmitting antenna gain and its influence on Ad

The purpose of a GPS transmitting antenna is to illuminate the Earth surface in

the field of view of the satellite with a uniform strength.

The GPS transmitting antennas present patterns properly shaped to

compensate for the path loss occurring at low elevation angles. The path loss of the

signal is a function of the distance between the antenna phase center and the point

on the surface of the Earth where the GPS receiver is located. The path loss is

minimum when the satellite is at 90 ° elevation angle (at zenith) and is maximum

when the satellite is at 0" elevation angle (at the horizon). A comparison between the

pattern of an ideal antenna pattern and a typical GPS antenna is shown in fig. 2.6.

The edge of the Earth in view subtends an angle of approximately 27.74 * from

the GPS satellite altitude. The satellite antenna pattern extends behind the edge of

the Earth, as shown in fig. 2.7. The transmission power from the satellite is not

uniform with the angle of bore-sight of the satellite. The beam transmits more

power toward the Earth's limbs, so that low elevation angle measurements on the

ground will see more power.

The direct signal Ad is a function of the signal strength transmitted by the

satellite, Atrans , and also of the transmitting antenna pattern Gt(O,0), where 0 and 0

are elevation angle and azimuth of the satellite, respectively:

Ad = Ad(8,0) = Atrans Gt(0, ) [2.31]

-2.1 dB

DEAL ANTENNAPATTERN

Figure 2.6: Comparison between the antenna patterns of an ideal GPStransmitting antenna and a typical one (Parkinson, 1996).

f a 1227 MHz: a = 45", 225*L2 FREQUENCY

72 36 0 36 72f = 1575 MHz: w = 450, 2250

L1 FREQUENCY

Figure 2.7: Antenna patterns of a GPS transmitting antenna at LI and Lz.Block II satellites (Parkinson, 1996).

. -an•

22.6.2 GPS Receiving antenna gain and its influence on Ac

The signal strength received by the ground antenna ( A) is also a function ofthe receiving antenna gain Grec(O,4).

GPS receiving antennas present a low directive gain, to acquire datasimultaneously from as many visible satellites as possible. This implies that multipathsignals scattered from any positive elevation cannot be rejected during the dataacquisition.

The fact that GPS antennas have a non zero gain below the horizon, representsa trade-off between the need of rejection of reflected signals and the attempt toreceive direct signals at low positive elevation angles with a reasonable gain.

But why are data incoming from low elevation angles so important? Data fromlow elevation angles are useful to reduce the correlation between estimates of thevertical component of the site position and estimates of the corresponding zenithpropagation delay.

Because of this dependency of A, on the receiving antenna, the pattern of thesignal strength follows the antenna gain pattern, showing lower values for lowelevation angles and higher values for high elevation angles.

The performance of each particular GPS user antenna has a great effect on theaccuracy and precision of the GPS measurements. The antenna patterns of some ofthe most commonly used receiving antennas are shown in fig. 2.8 and 2.9 (Shuplerand Clark, 1994). These measurements were performed in an anechoic chamberand represent the results for the azimuthally averaged LI amplitude patterns of theantennas, measured as the antenna zenith angle was varied.

-10

-20

-30

-I()

-180 -120 -60 0 60 120 180

Zenith Angle (deg)

- ar-r ,- - -Dor-aIgolan A&MeOKm lowrafy

Figure 2.8: LI relative amplitude patterns of GPS user antennas: Dorne-Margolin

and Ashtech. (Shupler and Clark, 1994).

0

-10

-20

-30

-40

r-0%- 80 2-180 -120

- Wkrrwco

-60 0 60 120 18C

Zenith Angle (deg)- - - Iat. 1,

kt~vWo4

Figure 2.9: L2 relative amplitude patterns of GPS user antennas: Trimble, TexasInstruments, Macrometer and Wilmanco. (Shupler and Clark, 1994).

- . Astech

wrh aM 1rygaWQJIa'

2.3 GPS receivers in presence of multipath

2.3.1 GPS receivers

Multipath reflections affect both, the signal amplitude (SNR) (section 2.2) and

the carrier phase measured by the Phase Lock Loop (PLL). In this section a brief

discussion on GPS receivers is presented, with particular attention to how multipath

noise is processed in the DLL (Delay Lock Loop) and the PLL.

A GPS receiver is constituted of several components (hardware and software) that

process the incoming signal from a GPS satellite.

The GPS carrier signal is biphase modulated with C/A and P-codes. When it is

received by the antenna, it is first filtered by the receiver (in preprocessing mode) in

order to eliminate unwanted RF (Radio Frequency) environment from the desired

GPS signal band.

Because GPS signals are spread spectrum signals, it is necessary to up or down

convert them in order to reallocate their spectrum. The Down-Converter in the

receiver mixes the LOs (signals from the Local Oscillator), generated by the

frequency synthesizer, with the amplified RF input to obtain a shift of the frequency

spectrum of the signal to IF frequencies.

The IF signal obtained after down conversion, is then converted to a baseband

signal composed of in-phase (I) and quadraphase (Q) signals.

State of the art GPS receivers, after sampling and quantization, split the signal

processing into multiple channels for simultaneous tracking of multiple satellites, by

using the CDMA (Code Division Multiple Access) method.

Each satellite is tracked by the Delay Lock Loop (DLL) and the Phase Lock Loop

(PLL). These devices assure that the incoming codes and carrier phases are

matched (or locked) to the receiver-generated codes and phases, and remain locked

throughout the tracking of continuously received signals. Code matching directly

generates the pseudorange and the phase matching generates the ambiguous carrier

phase observable.

GPS satellites transmit highly coherent radio signals with right-hand circular

polarization over two L-band channels, LI (1575.42 MHz) and L2 (1227.60 MHz).

The LI carrier signal is modulated by two pseudo-random (PRN) sequences: the P-

code (precision code, 10.23 MHz) and the C/A code (coarse code, 1.023 MHz). L2

carrier signal is modulated by the P-code, only.

When Anti-spoofing is activated, the GPS signal is intentionally corrupted. AS is

implemented through a modification of the P-codes: authorized users are equipped

with a decryption devise, in order to lock on the P-codes.

If the P-code is available, both carriers can be reconstructed by the code

correlation technique.

If only the Y-code is available (i.e. the encrypted P-code), the LI carrier can still

be reconstructed by code correlation using the C/A-code, but a codeless technique

needs to be applied to reconstruct the L2 carrier.

Some of the codeless techniques commonly used are the L2 squaring

(Macrometer), the Cross-correlation of L2 with LI (Trimble and Rogue), and the z-

tracking mode (Ashtech).

2.3.2 The DLL and PLL in the presence of multipath

The main operations performed by a receiver are the tracking and the locking. A

receiver is code-locked when the code internally generated by the receiver has been

aligned with the received code from the satellite. The tracking consists in shifting

continuously the receiver code to match the incoming signal. This shifting of the

locally generated receiver code is controlled by the Delay Lock Loop. The

discriminator function (which is defined to identify the maximum of the correlation

between the internally generated signal and the GPS signal) is zero when the time

tracking error is zero. In the presence of multipath the zero crossing of thediscriminator function value is shifted in time by 8, the time delay of the reflected

signal with respect the direct signal. Moreover the discriminator function is

modulated by the reflection coefficient of the scattering surface and by cos(p-80),where p and 801 were defined in [2.4] and [2.5].

After removing the PRN code in the DLL, the unmodulated carrier wave is passedto the PLL, where the phase measurement is performed. The result is the phaseoffset between the received signal and the reference signal generated in thereceiver. In the presence of multipath the carrier tracking error is the multipathphase error 80.

2.3.3 L2 signal processing in the presence of AS

(Anti-spoofing)

AS can severely limit the use of GPS for high accuracy positioning for unauthorizedusers. However there are several solutions proposed for dealing with AS, which areimplemented by the GPS receivers.

Because L2 is biphase-modulated (by either the P-code or the C/A code), it ispossible to recover the Lz carrier without knowledge of the P-code, by simply

squaring the signal or cross-correlating Lz with LI. There is noise degradation added

in this codeless carrier recovery, because of the non-linear squaring operation or the

cross-correlation with a noisy signal (L). Other new techniques, such as z-tracking,are used in new receivers, which presents better characteristics of the SNR.

2.3.3.1 L2 signal squaring

Signal squaring is one of several methods used to recover the pure carrier from the

biphase-modulated signal. Autocorrelating the received signal (squaring) all

modulations are removed, because a 180' phase shift during modulation is equivalent

to a change in the sing of the signal. As a result of this processing , the signal

frequency increases by a factor of two and the effective wavelength is half-wavelength

carrier phase observation L2. A serious drawback of this method (not any longer in

use in the new receivers) is also that the SNR is reduced by 30 dB with respect to

the code correlation technique..

2.3.3.2 Cross correlation of L2 with Li

This technique is based of the fact that both, LI and L2 carriers are modulated

with the same P(Y)-code, although the Y-code is not known. Due to the dispersive

nature of the ionosphere, the propagation of the electromagnetic signal is different:

the Y-code on L2 is slightly slower than the one on LI. The time delay necessary to

match the LI and L2 signals is a measure of the travel time difference between the

two signals.

The result of the correlation process between LI and L2 are the range difference

between the two signals and the phase difference between the beat frequency

carriers. With this method the SNR decreases of 27 dB with respect the code

correlation technique, reporting a 3 dB improvement with respect L2 squaring.

2.3.3.3 Z - tracking

This quasi-codeless technique is the most recent and provides the best SNR

performance in the presence of AS. This technique is based on the fact that the Y-

code is the module-2 sum of the P-code and is a substantially lower rate encryption

code. The LI and L2 signals are separately correlated with locally generated P-codes.

Since there is a separate correlation on LI and Lz, the W-code on each frequency can

be obtained. The encryption code is estimated for each frequency and removed

from the received signal to allow locally generated code replicas to be locked with

the P-code signals of Li and Lz.

With this method the full-wavelength carrier phases of L and L2 is obtained. The

output pseudoranges and phases of the Z-tracking technique, are directly those

which would be obtained by a code correlation without antispoofing, but with a SNR

degradation of 14 dB.

Chapter 3

Description of the algorithm for the

Multipath Phase Error Estimation

from the SNR data

3.1 Introduction

Among other sources of noise, multipath phase errors represent a significant

limiting factor in high precision GPS positioning [Parkinson and Spilker, 1996]. By

using differential techniques in dual frequency mode it is possible to eliminate the

most of the GPS errors (clock errors, ionospheric effects, etc. ...). However, the

multipath phenomenon is characteristic of the surroundings of the receiving antenna

and needs to be corrected with other more local techniques.

Multipath reflections affect the SNR (section 2.2) and the carrier phase

observable measured by the Phase Lock Loop (PLL) (section 2.3).

In this chapter we describe the algorithm implemented for the estimation of the

multipath phase error from the frequency and amplitude of the oscillations of theSNR data.

3.2 Errors in the GPS Phase Measurements

The dominant source of error in phase measurements is the clock error betweenthe transmitter (satellite) and the receiver (ground station).

To eliminate the effects of bias or instabilities in the satellite clock, differential

GPS methods can be applied. One method consists in computing the single-

differences, by differencing the phases of signals received simultaneously by two

ground stations. If the receivers are closely spaced (short baseline) the computation

of the single difference phase residual also reduces the effects of tropospheric and

ionospheric refraction on the propagation of the radio signal.

The effects of variations in the station clock can be corrected by computing the

double-differences phase residual. This observable is obtained by subtracting the

single-difference phase residuals relevant to the two satellites from one other(double-differences).

Apart from clock errors, other significant sources of errors in GPS positioning are

due to orbital errors, phase center models, ionospheric and tropospheric effects,multipath, and noise in the receiver. It is usually difficult to distinguish among

different errors, especially between ionospheric and multipath effects, because they

can produce similar oscillations in the carrier phase.

The spectrum of the ionospheric variations is a function of the elevation angle of

the satellite, the time of the day, the season and solar activity. The dispersive nature

of the ionosphere produces a different effect on the signal at different frequencies.

By combining the two carrier beat phase observations, LI and L2, it is possible to

remove the ionospheric contribution. This is the reason why GPS satellites transmit

in two different frequencies, f1 (1575.4 MHz) and f2 (1227.6 MHz).

One way to filter the ionospheric effects is to apply the so called dual-band

processing. It consists in computing a linear combination of LI and Lz (LC):

LC = S~ = 2.546.- L - 1.984- L2 [3.1]

In the following chapters we will denote LC with QDobs and we will refer to it as

the observed phase residual.By computing IQoBs the effects due to other sources of error (different than the

ionosphere) are magnified. This is the reason why, for short baselines, where theionospheric errors cancel out with single differencing, it is preferable to treat LI andL2 as two independent observables. For long baselines (more than a few kilometersapart) the ionospheric errors are uncorrelated and it is necessary to use the dual-bandprocessing (computing LQC) to eliminate all the effects of the ionosphere.

In general we would like to eliminate both, multipath and ionospheric effect.For short baselines LI and L2 can be treated as two independent observables, thuseliminating the need for calculating LC, which in return would amplify the multipatherror.

For long baselines, the ionospheric effects are not strongly correlated and it isnecessary to use LC in order to eliminate them. The ionosphere does notdecorrelate after a few kilometers. It is in fact correlated for many hundred's ofkilometers. But how large is the decorrelated part? An approximate rule (discussedin many of the early papers on GPS) is that the differential ionospheric delay isbetween 1-10 parts-per-million of the separation between the sites, where the exactamount depends on latitude, time of day, time of year and solar activity. Using thisapproximation, for baselines of 1 km, the ionospheric contribution is likely to bebetween 1 and 10 mm. 1 mm is small compared to the phase noise, but 10 mm (0.05cycles) is large. Therefore, when the ionosphere is active, dual frequency may beneeded on baselines as short as 1 km.

When only distant receivers are available, it is usually necessary to compromisebetween the amplification of other types of noise and the need to eliminate theeffects of the ionosphere by dual band processing.

Either case (short or long baselines) the multipath error cannot be filtered withdifferential GPS techniques, because it is a distinct characteristic of the environmentaround one particular receiver.

One technique for the estimation and correction of the multipath error isproposed in the following sections.

3.3 Multipath Phase Error EstimationAlgorithm

The algorithm proposed in this thesis manipulates the variations of the SNR forthe estimation of the total multipath phase error 80EST, computed as the

superposition of several single reflections.With reference to fig 2.1, the amplitude of the direct and multipath signals are

assumed constant for the time T, in which Am rotates around the tip of Ad. Duringthis time the angle j3 varies of at least 360" and the composite signal Ac shows an

oscillation of period T. This implies that the amplitude of the direct signal arrivingto the antenna and the multipath frequency fm are constant over T.

3.3.1 Antenna Gain removal

The first step of the estimation algorithm consists in removing the variations of

the SNR due to change of position of the satellite. This changes are due to the factthat the direct GPS signal reaches the receiving antenna under different angles (0,4) which are associated to different values of the antenna pattern.

In order to remove the antenna pattern contributions and the differences in thetransmission power from the satellites, we fit a 4-th order polynomial in sin(elev) to allof the SNR data at each station. In this fit we include a zero-order term (i.e. aconstant offset) for reasons to be discussed below. Separate fits are made for LI andL2 data. With L2 data a distinction is made between data processed in cross-correlation mode and those data that are directly tracked. The latter occurs for the 1or 2 GPS satellites that do not have Anti-spoofing turned on. This fitting processesalso normalizes the gain-corrected SNR data so that they are near unity. Thepolynomials estimated with the procedure previously described look similar to the

jc1-~~l~- ·--I -------·- ~.

anechoic chamber gain curves but tend to be larger in the mid-elevation angle range.

This discrepancy is probably be due to the effects of the transmission power from

the satellites.

For all receivers, except the Ashtech z12, the measured SNR and the gain

curves tend to approach zero as the satellite elevations tend to zero. (See fig. 3.2) .

For Ashtech z12 the SNR near zero degrees elevation angle is still about 90% of its

value at zenith. This behavior is not consistent with the gain pattern of the Dorne-

Margolin antennas used with these receivers. Therefore, it can only be explained by

increased integration time at lower elevation angles (thus increasing the SNR) or by

the SNR values being biased. After comparing Ashtech and Trimble SSE data

collected on the same site (and showing similar multipath signals), we concluded

that latter was more likely explanation. This is the reason why we include an offset

term in gain fitting process and simply remove this offset from all the SNR values.

In the algorithm a problem with the gain removal is represented by the

dependency of the SNR on the elevation and azimuth angle, as well. The main

dependency is the elevation angle, but not taking in to account the azimuthal

dependency an error is introduced in the estimation, which influences the

performance of the algorithm. The main dependency is with elevation angle, but for

Trimble SST and SSE antenna there is a sizable azimuthal dependence that we have

not accounted for. The impact of this neglect has not been evaluated and is likely to

influence the lower frequency multipath signal estimation.

The impact of the antenna gain on the SNR depends on the particular signal

processing procedure performed by each receiver. For receivers which use the L2

squaring techniques, the SNL.Lz is a function of the elevation angle and decreases

as the square of the L2 gain pattern of the antenna. In receivers which use the cross-

correlation between LI and Lz, the SNRL2 decreases as the product of LI and Lz

gain patterns. In receivers which perform the standard tracking the SNRLL2

decreases simply as the gain pattern.

In the algorithm, the SNRL2 derived from the receivers which performs L2

squaring and standard tracking, can be processed directly. But the SNILLz deriving

from an operation of cross correlation needs to be either divided by SNRILI (so that

SNRILz / SNR1LI is the input for the algorithm for the estimation of the L2 phase

error) or considered without modifications. In the first case the estimated phase

error is directly 80 2 and, in the second the estimated phase error is given by the

difference between the phase error estimated from SNRL2 (8D'2) and the one

estimated from SNR-LI (8•1). In other words: 802 = (8D'2) - (801) . For the

estimation algorithm proposed the first technique was adopted.In figure 3.2 the SNR for LI for the station MANA (Turborogue) and the

satellite PRN 26, is show, as a function of time. As it can be noticed comparing fig.3.1 with fig. 3.2, the SNR as obtained from the receiver is strongly dependent on

the elevation angle of the satellite. After the gain removal and normalization, the

estimation algorithm is ready to manipulate the new SNR for LI shown in fig. 4.3.

station: MANA satellite: PRN 26

1.5 2 2.5 3 3.5 4 4.5 5 5.5 6Time (sec) x 10'

Figure 3.1: Elevation angle for the satellite PRN 26

SNR Li as received by the antenna

.5 2 2.5 3 3.5 4 4.5 5 5.5

Figure 3.2: SNRILL forPRN 26.

time lsec] x 10'

the station MANA (Turborogue) and the satellite

4:00 6:00 3:00 10:00 12:00 14:00 16:00

Figure 3.3: SNRLI for the station MANA after gain correction and

normalization.

700

soo -

C400

300oo

C 200 -

100

I i l |

800

II1 1 6

7

I--

3.3.2 Data Segment Selection

After the gain correction, the SNR is divided into segments. The length of thesesegments is based on gaps that the data might have, or on the rate of change of theelevation angle, so that portions of data relevant to a rising or setting satellite aretreated separately.

The SNR might have missing data in the sequence due to problems with thereception of the signal or to obstruction of the satellite. The algorithm presents agap tolerance of about 10 epochs. If the missing data are less than 10 points, theprogram linearly interpolates before the computation of the spectra. However, thealgorithm does not interpolate when fitting the sine and cosine components,because the interpolation introduce false data which might produce a wrongestimation of the phase error. On the other hand, not having enough data for theestimation of the sine and cosine components, can cause anyway an inaccurateestimation of the phase error. If the gap is too large, separate analyses are done forthe two segments of data. Because the length of the segment of data determines thefrequency resolution, also a too short time series can lead to a wrong phase errorestimation.

3.3.3 Spectral Decomposition of the SNR

As already discussed in section 2.2.4, the scattering phenomenon is generallydue to the superposition of several single multipath contributions, each characterizedby a specific frequency fm. Multipath is not a stationary phenomenon because its

frequency varies with the rate of change of the satellite elevation angle (formula[2.5]). Therefore, spectral estimation must be performed on a span of data longenough to provide the required frequency accuracy, but short enough to allow thehypothesis of constant frequency.

The purpose of the spectral estimation performed by the algorithm is todecompose the total multipath phase error in several components and isolate themto compute the GPS phase error due to each component. The multipath

46

contributions are determined sequentially and the correspondent phase error arecomputed. The total phase error BQ1 EST is created from the sum of the complexcomponents of all of the contributions.

We decompose the SNR variations into individual components in an iterativeprocedure. At each iteration, we compute the power spectra of the current SNRresiduals, which in the first iteration are simply the values of the SNR after weremove the gain corrections. We select the frequency with the largest amplitude: ifthis amplitude (sqrt of the power spectral density) is larger that 1/500 of the meanSNR strength (obtained from the zero frequency component in the PDS) then theiteration is continued. The 1/500 limit is set so that the phase contribution from theremaining components will be less than 0.4 mm (190 mm/ 500).

For each period of the maximum frequency through the data segment, we estimatea mean value and sine and cosine components at this frequency. Since thefrequencies are obtained from a FFT, we are assured that there will be an integernumber of these periods in the data segment. As can be seen in fig. 3.4, forexample, the frequency of the multipath is reasonably constant but the amplitudechanges with time. Our algorithm estimates separate sine and cosine componentsfor each full wavelength through the data segmant. The sine and cosinecomponents are saved and the contribution to the SNR computed and removedfrom the SNR values. These residual SNR values are then used in the next iteration.In addition to the 1/500 amplitude limit, the iteration is continued for no more than50 iterations although this limit is rarely reached. At the end of the spectraldecomposition, we have a series of sine and cosine components, each applicable todifferent times in the data depending on the frequency they represent. For eachdata epoch, there are N applicable component pairs, where N is the number ofiterations. The compex sum of the N pairs (with their time arguments dependenton the frequency they each represent) is formed and the phase error and amplitudecomputed from the sum. The N multipath contributions estimated with thealgorithm are superimposed in figure 3.6, to provide the total multipath phase error

There are limits on the spectral components estimated. When the maximumspectral components are found, we search frequencies for 2/T to n/(2T), where T isthe total duration of the segment, and n is the number of measurements in the span.

Because the high frequency end is half of the maximum frequency in the spectrum,

the algorithm will tend to smooth the SNR as well. This smooting can be observed

in fig. 3.4.

As explained in section 2.2.2, the determination of the sign of the multipath

phase error estimate remains ambiguous. In the algorithm the sign attributed to the

multipath phase error is based on the sign of the rate of variation of the elevationangle (dO/dt). The sign actually depends on the rate of change of distance to the

reflector. Because we never try to compute the location of the reflectors, we use therate of change of the elevation angle instead. If dO/dt is positive, 86EST=-atan2(Imag,Real); if If dM/dt is negative, 8&EST=+atanz(Imag,Real). The assumption

made is that, as the satellite rises, the distance to the reflector decreases (at least for

reflections from a flat Earth). This is verified in most of the cases, but it is not true

in general. This ambiguity in the sign of the multipath phase error strongly

influences the performances of the estimation algorithm in those case when an

abrupt change of sign of the estimated phase error is observed.

The total multipath phase error estimate 8IDEsr is shown in figure 4.7 and is

indicated with LCGEST. The observed phase residual measured from the GPSmeasurements 8G0OBs is shown in the same figure (LCOBS) and compared with the

estimated phase error due to multipath. In this example, the visual correlation of the

two curves is striking: the frequency content and the amplitude of the two curves

seems to agree very well. In the following chapters, quantitative analyses (spectral and

statistical) are performed to compare estimated and observed phase residuals.

KKAU SNRL1 PRN 16 ASIA1995 6 9

4.4 4.5 4.6time (sec)

4.7 4.8

1.4

1.2

1

0.8

4.

2

1.8

1.6

1.4

1.2

4.4 4.5 4.6time (sec)

4.7 4.8

Figure 3.4: Curve fit for SNRLI satellite PRN 16. Station KKAU.

3II I

2

1.8

1 r-

................................ .................. i.....

. .. . . . . .. . . . . . . . . . .. .. . . . . . . . . . . . .. . . . .-

....

1

0.8

4.

4.9

x 10

3 4.9

x 104

SI I

I

I ,

· ·

i I

. . . . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . .. . . . . i. . .......-. ..........................I I

KKAU SNR L2 PRN 16 ASIA 1995 6 9

4.4

4.4

4.5

4.5

4.6time (sec)

4.6time (sec)

4.7

4.7

4.8

4.8

Figure 3.5: Curve fit for SNRIL2 satellite PRN 16. Station KKAU.

INI

.

2

1.8,4 I•'

1.0

1.4

1.2

1

0.8

4

2

1.8

1.6

1.4

1.2

0.8

4.

...... . . ..

F,

3I I I ~I ' I II ~ I

3

4.9

x 104

4.9

x 104

-c

3

6

. . . . .· -- - -- .' .· . .. . . . . ..

Im

Re

Composition of multipath single components.Figure 3.6:

GPS "OBSERVED" Phase Residuals for: KKAU PRN 16

4.4 4.5 4.6 4.7 4.8GPS "ESTIMATED" Phase Residuals computed from the analysis of SNR variation

0.2

0.1

0

-0.1

-0.2

4.

0.2

0.1

0

-0.1

-0.2

4.

0.2

0.1

0

-0.1

-0.2

4. 4.4

4•I

4.5 4.6Time (sec)

4.7

4.8

4.9

x 104

4.9

x o10

4.8 4.9

x 104

Figure 3 .7: The multipath phase error ( DEST = LCEST) estimated by the algorithm iscompared with the observed phase residual (60oBs =LC.OBS) computedfrom the measurements.

. ... . . I.10.. .. ... ... .. ... ... .. ... .. .. -. . . . . . . ......... - --

,............... . ................ ................ : ................ :..... v/

3

3 4.4

.................... .. . . . . ........................ ... . . . . . ... . .. ..... .. .. .. .. . .. . .

.................. ...... ...... ... .. ..

. ......... ......... ........ . ......... . ....... .

3

........ .. .. . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .

................. ..........· ·--··

.

.. ... . ..

........ .... ..... .................. . ...................... ......... .....

4.5 4.6 4.7Comparison LC OBSERVED vs LC ESTIMATED

1

· '~'1

· `''~

I ....

Chapter 4

Statistical and Spectral Analysis of

estimated and observed GPS phase

errors

4.1 Introduction

The aim of the spectral and statistical analysis described in this chapter is to test

how well the retrieved multipath phase error from the Signal-to-Noise-Ratio (SNR)

agrees with the phase error observed in the GPS measurements. To this purposetwo time series, the observed phase residual (4OBs = 8sOBs) and the estimated

multipath phase error (EST = B EST), were studied and compared. This analysis

provided important information about the applicability, limits and performance of the

GPS multipath estimation method described in chapter 3. The results of this study

applied to actual GPS measurements are discussed in detail in chapter 5.

4.2 Data Preprocessing

With data preprocessing we indicate the procedure for the selection and

formatting of the GPS data before applying the analysis. The first goal of this

operation was to choose data sets containing a strong multipath error in the phaseobservable.

As mentioned in chapter 2, the occurrence of multipath produces large regular

oscillations in the SNR. However, the simple analysis of the SNR might not provide

enough information for evaluating the characteristics of the data, as ionospheric

effects can also cause wave-like patterns in the signal received by the antenna. A

discussion on the errors in the GPS phase measurements can be found in section3.2.

Because the observed phase residual, 40BS, does not contain ionospheric effects,the combined analysis of SNR and oBas gives enough information for the selection ofthe data. Whenever large structured oscillations were found in both SNR and 0oBs,

because in the observed phase residual the ionospheric effects are filtered out, wecould be confident in having GPS measurements affected by multipath, and the datawere considered appropriate for the analysis.

0oBs was computed by using the GAMIT GPS analysis software packageimplemented at MIT (King and Bock, 1993). The data chosen for this analysis wereselected by using the CVIEW option of the program.

The data sets chosen were then divided into subsections having well definedstatistical properties and multipath interference. This operation permitted us toisolate the phenomena without averaging out the effects of multipath over a largenumber of samples.

4.3 Spectral Analysis

4.3.1 Multipath frequency

The multipath phenomenon is caused by the interference of electromagneticreflections with the direct electromagnetic signal transmitted by the satellite. Thelevel and frequency of the GPS noise deriving from multipath depends upon thedistance, geometry and reflectivity of nearby objects, the elevation angle of thesatellite and the rapidity of change of the elevation angle with respect the receiver,and the value of the carrier frequency (section 2.2).

Because of the dependency of multipath on these parameters, each multipathcomponent due to a particular reflector have a distinct frequency. Therefore, themultipath noise caused by the surrounding of a receiving GPS antenna can bestudied and identified by spectral analysis (section 3.3.3).

Spectral analysis is used here to compare the estimated multipath phase error(~Esr) and the observed phase residual (oBs).

4.3.2 Power Spectral Density

In spectral analysis we try to represent a stationary process in terms of a sum ofsinusoids, in order to define its spectrum. We applied this analysis to the observedand estimated phase errors, to determine their spectral content and how this wasrelated to the multipath phenomenon.

The two time series (1 oBs j and {ESTr J, are assumed Stationary Ergodic Random

Processes. In other words, we infer that their statistical properties do not vary withtime (Stationary) and that the average values computed over the ensemble at a time

t0, 0x i (t) [ for x = OBS, EST), will equal the corresponding average values computed overtime for a single time history record, X(t)[ for x = OBS, EST} (Ergodic).

This important assumption allows us to perform our statistical and spectral analysiswithin one time series, without the need of independent realizations of the process.

Let us consider a stationary ergodic random process:

{,t} = f{(n. At)} for n = 1,2,3,...,N. [4.1]

where the time resolution interval between the sample values is At , the total number

of samples is N and the total length of data analyzed is T=N At.

The Discrete Fourier Transform (DFT) of {1j is defined as:

{)K } = {(k -Af)} = At m4(e('N• for k = 1,2,3,...,N. [4.2]

The Nyquist cutoff frequency of the sequence is f, = 1/(2 At ), and the minimum

frequency-resolution bandwidth is Af = 11T =1/N At.

Therefore, the Power Spectral Density of {1,} is given by:

2 2 [4.3]N. AAt

For each couple of time series, {OBSn)} and {ESTnrj, we computed the Power Spectral

Densities Sos , SES, and SDIFF, power spectral density of their difference {ODIFF).

Each time series was previous normalized by subtracting its mean. The DFT was

computed via FFT (Fast Fourier Transform).

The Power Spectral Density was computed by using a Matlab algorithm

(FFTobsest.diff.m) which can be found in Appendix C.

4.3.3 Auto Correlation and Cross Correlation

An other way to compare f{oBsJ and {(ESr) is to compute the Auto-Correlation of

each of the two time series (Roo and REE) and the Cross-Correlation between them

(RoE)To define Roo, REE and ROE between two time series {0OBSn) and {4 ESTn, we first

introduce the Cross-Covariance Function, CoE.

The Cross-Covariance Function between two processes I{OBsnj and {ESTr)j for anytime delay t, is given by :

COE(r)= (OoBSn -OBS)(OES(t+r) - EST (t + ')) [4.4]

If we assume again that the two time series are stationary ergodic processes, theirmeans •ROBs and grsr are constants and independent of t. Therefore, COE can be

written as:

COE( (O=BSn~ )(ESTn(t + ) OBSMEST [4.5]

We define the Cross-Correlation function between {JoBsJ and {•EST) as:

•E) = I oBSnX)(ESTn (t + r)) [4.6]

and it follows that:

COE ( = ROE()- OBSuEST [4.7]

The equivalent Auto-Covariance Functions for the time series are:

1F[4.8]

CEE()- (tES-Tn -f r S)(O Tt + -EST t(t + a)

and the Auto-Correlations for (os~s and {•--J are:

Roo (T) = [ XOBSn)(OBSn(t + )

[4.9]

RE(') = SY- (ErXrn)( ESr,(t +)

Therefore:

Coo(T)= Roo( ) -oss [4.10]CEE() = REE() 2

If the mean of either measurement is zero (p=0, = =0 or p.,=C=0 ) it follows that:

Coo(r)= Roo(r)

CEE () = REE( ) [4.11]

COE( )= ROE(r)

The Matlab program implemented for computing the Auto and Cross-Correlation

of {(OBs) and {(ESTn) is called Auto-CrossCORR.m, and is presented in Appendix

C.

4.3.4 Auto and Cross Spectral Density Function

The spectral density function between two stationary ergodic random processes

can be defined as the Discrete Fourier Transform of the Correlation function

between those records:

N 2 kn

SOE(k)= At ROEe N for k=1,2,3,...,N. [4.12]n=l

The two correspondent Auto-Spectral density functions for {oBs and {(-r}) are,

therefore:

Soo (k) = At Rooe N for k = 1,2,3,...,N.n-1

[4.13]

SE(k) = At XREe-JN) for k= 1,2,3,...,N.n-1

The Matlab algorithm for the computation of the spectral density via correlationfunction is shown in Appendix C and is called SPCORIRobs-est.m.

4.3.5 Coherence Function

The frequency relationship between {loBSn) and {IEST.) can be also studied bycomputing their coherence function, 720E. The computation of Y2 oE providesinformation on what fraction of the power in 4 EST can be explained by OBS i.e.which fraction of the total Phase Residual is due to multipath.

The results of this analysis allow us to recognize the range of frequencies for whichthe two sets of data under analysis present an high correlation. In general this test isused to verify and study the results obtained from previous Spectral Analysis.

The Coherence function computed was defined as:

2 S0E [4.14]YOE = [4.14]

The algorithm implemented for the computation of the coherence function(Coherenceobsest.m, Appendix C) divides the total time interval of the twoprocesses in subsections. The number of these subsections depends on theparticular data set considered. Several numbers of subsections are examined (2 to12) and after several trials the more appropriate number is chosen. Because of thesampling, the maximum value does not necessarily indicates the maximum of the

coherence function. The only information we can extract from the coherencefunction computed in this analysis is the range of frequencies where the two timeseries correlate better.

4.4 Statistical Analysis of GPS Phase Residuals

In this section we compute the statistical properties of the variance estimates ofGPS phase residuals. The procedure followed in the statistical analysis presented inthis section is analogous to the one derived in vanDam and Herring, 1994.

For each set of data, the observed phase residual from the GPS measurements,the estimate of the phase error due to the multipath effect, and the phase residualafter correction, can be written as functions of the noises affecting the GPSpositioning. In order to assess the statistical properties of the phase error before and

after the correction for multipath, we can define:

'OBS = WMPN + VMN

PEST = WMPN + VEN [4.15]ODIFF = OOBS - 'PEST = VMN - VEN

where:

OOBs = Phase residual observed directly from the GPS measurements

WMPN = Multipath phase error ("true" multipath phase contribution)

vMN = Noise in the measurements due to other sources different from multipathOEsr= Multipath phase error estimated from the SNR data

vEN = Noise in the retrieval of the multipath phase errorPDIFF = Phase residual after the correction for multipath

In this analysis it will be assumed that the time series under study are stationary

ergodic, with zero mean and standard deviation o.

Of all the quantities previously defined, only 0oBs, mEST and PDIFF are known, and

the unknown phase errors vMN, VEN and 4 MPN are assumed to be independent.

A very useful method of statistical analysis is the Chi-square test, where the Chi-

square distribution (with N-1 degrees of freedom) is given by the estimates of thevariance normalized by the expected variances. However, because OBS, EST and

PDIFF and the estimates of their variances are correlated, a simple Chi-square test

cannot be used to determine the statistical significance of the changes in the

variance estimates, due to the correction for the multipath phenomenon.

In order to perform an appropriate statistical analysis, we computed the

expectation and variance of the difference between the variance estimates of the

phase error, before and after applying the corrections for the multipath contribution.

If N is the number of samples and a the standard deviation of the time series, the

estimates of the variances of {oBs J, {4ESTn }, and {fDIFFn) are given by :

&2BS = 'V (OBSn)2 = N (VMN+MPNA 2

n=1 N-1 =i N-1

sr=$2EST L 2(0MPn+EN1) 2 [4.16]n=1 N-1 = =1 N-1

N(0 .2 MN + ENn 2&rIF n=1= N - 1 N1 N-- 1ln=l

It should be noticed that in these formulas the processes have been normalized by

subtracting their mean before computing the variances.

The expectation of the estimates of the variance can be written as:

(UE2T)1= OMpN + ENM

(&2",)= acN + al.

The expectation of the difference of the variance estimates of OOBS and DIFF iSgiven by :

(BS &D = -[4.18]

The variance of the difference in the variance estimates is :

var(BS - F) s DIFF s - FF)

If we assume that:

[4.19]

(vNolM) = 0 and (vM, vENi) =0

(OMPNiOMPNj)= ( vMN vMN) = (vENi EVj) =0 for each i j

then the variance of the difference in the variance estimates can be written as:

&2r2cS =4. qFN - 1 + 6var(OSS &DN-1 [4.20]

where oMN, aEN and (MPN are unknown, and can be retrieved by inverting the

system:

( S)= -2MN + 2PN

(sr)= oPN + o [4.21]

(&DIFF) = +U

[4.17]

for each i

Chapter 5

Applying the method of multipath

estimation to GPS data

5.1 Introduction

In this chapter we discuss the results obtained from the phase error estimationalgorithm applied to GPS measurements. In particular, three GPS data sets werechosen for this study and will be discussed in the next paragraph: the Tien-Shandata, the LIGO data and the IAP data. Among these three collections, 42 data sets,acquired between June 1995 and January 1997, were selected for multipathestimation and analysis.

Although these measurements were not originally intended for studyingmultipath effects on GPS measurements, they are suitable for testing the

performance of the method for their strong multipath contribution to the phase error

observable.

A brief description of the data sets selected, their characteristics and their

significance in this study are provided in section 5.2.

5.2 Description of the GPS stations andthe data sets analyzed

5.2.1 The Tien-Shan data

This data set was acquired during the 1995 -1996 Tien-Shan field project. The

original purpose of this campaign was to define a north-south deformation across

Tien-Shan and to study the interaction of the strike-slip faulting and thrust faulting

along the Talaso-Ferghana fault.

The two stations selected for the multipath analysis, KKAU and MANA, are part

of a network of approximately 95 sites. The network stretches across three of the

former Soviet Republics, a region extending from Uzbekistan east to the Chinese

border, and from Taldy-Kurgan (Kazakhstan) south to Tajikistan.

The station KKAU is located in Kazakhstan, at 41.695248" lat., 72.893497* long.,and 1423.2 m elevation and uses a Trimble antenna as a receiving antenna.

The station MANA was located at a seismic observatory in the town of Manas, 30

km east of Talas, in Kyrgyzstan Oat. 42.493067, long. 72.497956%, elev. 1423.2 m).

The receiving antenna is a Dome Margolin antenna.

MANA was one of three permanent sites, besides POL2 and TALG. In the fall

of 1995, the receiver was moved to a new site near the town of Talas. This was a

better location for the receiver, because it was far enough from strong reflectors and

could be more easily mantained as a continuously operating site.

These two stations were chosen for the strong multipath effect present in the

phase measurements. Every time a GPS satellite was in a particular region of the sky,

a similar clear strong multipath was observed. This fact leads to the conclusion that

large reflecting surfaces were located near the receiving antennas.

However, the different frequencies of the multipath relevant to the two stations,suggests that the reflectors were located at different distances from the receivers.

Therefore, from the comparison of the results of the statistical and spectral analysis it

was possible to gain useful information about the performance of the estimation

algorithm at different multipath frequencies and for different geometries.

KKAU and MANA use different types of antennas, Trimble and Dorne-Margolin,respectively. The performance of the algorithm for data sets acquired with differentantennas was studied.

5.2.2 The LIGO data

This data set was chosen for the particular geometry of the surroundings of the

receiver 0036 ( fig. 5.1)

A strong multipath was observed when a satellite was at about 15' elevation and 45'

azimuth. Among the LIGO measurements two data sets, relevant to the stations0028 and 0036, had the same high sampling rate (At = 5 sec). These two stations are

located at close distance from each other. As mentioned in chapter 3, the

ionospheric errors can be filtered using single differencing when dealing with short

baselines. Therefore, in this case, it is possible to treat LI and Lz separately as two

independent observables, rather than their linear combination LC.

Both estimations were performed for the dual-frequency phase residual, LC, and

for the frequencies LI and L2 individually.

5.2.3 The IAP data

This data set was acquired in January 1997, in California, during a two week fieldwork carried out as part of a course on High Accuracy GPS held at MIT. The same

measurements were repeated at the same site in two successive days, but using two

different receiving antennas: Trimble (station COSE) on January 23, 1997 and

Ashtech (station GS29) on January 24, 1997. The measurements are relevant to the

same satellites at the same time of the day, shifted by 3.5 minutes to account for the

daily change in geometry.

Moreover, the two antennas present a different gain at low elevation angles.

Because of the antennas characteristics, the multipath error is perceived differently

by the two receivers, even though the actual multipath environment is maintained

the same during the two sets of measurements.

However, it should be mentioned that the weather conditions during the second

day of measurements (performed by the Ashtech antenna) were different. On the

second day of measurements (January 24) the ground was wet, due to persistant rain.

Rain usually increases the reflection coefficient of reflecting surfaces, which can

produces an higher multipath error in the phase observable.

To study how the multipath effects can change due to weather conditions, the

estimation algorithm was tested using data acquired on two different days, one sunny

and dry, and the other gray and rainy. Comparing the measurements performed with

the same receiver in the same location under these weather conditions, yielded very

interesting results.

GPS satellite:PRN 09

ceiver

1.5m

Fig. 5.1: Geometry of the surroundings of the receiver 0036 (LIGO data).

5.3 Multipath Estimation and Results ofSpectral Analysis.

5.3.1 KKAU and MANA

5.3.1.a) KKAU (TRIMBLE 4000SSE)

The data relevant to the GPS measurements acquired by KKAU on June 10, 1995

were analyzed. Large oscillations were observed in the SNR every time a satellite

passed through a specific region in the sky (low elevation angle and 50" azimuth).

An example of this phenomenon is shown in fig. A.1.1 and A.1.2. The SNR

presents large fluctuations when the satellite PRN 16 is at an elevation 0 = 10" - 20"

and azimuth 0 = 50" - 60", at the time t=4.5 - 5.0 10 4 sec.

The observed phase error determined from the measurement, OBss, and the

multipath phase error estimated from the SNR, 4 EST, are plotted and compared in

figures A.1.4 and A.1.7. In the plots, 0oBs and OEsr are referred to as LC OBS and

LC EST, respectively. The residual phase error given by the difference of these two

phase errors, DIFF, is plotted in fig. A.1.8.a) and is called LC DIFF. The observed

phase error shows very large values in correspondence of the structured oscillations.

The amplitude of ODIFF decreases significantly after applying the correction for

multipath.

To study the characteristics and frequency content of the three time series,(observed, estimated and residual phase error) the Power Density Spectra (PSD) was

computed and plotted in fig. A.1.8.b). The PSD of OBs and 4 ESr are very consistent

for amplitude and frequency content. They exhibit three narrow distinct peaks at

frequencies between 0.001 Hz and 0.01 Hz, and one large peak at a lower frequency.

The frequency content of ODIFF is not as rich as it is for 4 0BS and OEsr.

This result suggests that the contribution due to the multipath effect is filtered out

and the remaining phase error, which does not present a clear spectral content, is

due to other sources of GPS random noise in the carrier phase observable. In this

particular case, where the multipath effect has a predominant role in the observed

phase error, the estimation algorithm and multipath filtering is efficient in reducing

the phase residual, as well as the error in the final GPS positioning. However, a low

frequency residual component is evident in the PSD of 4 DIFF. This low frequency

component might be caused by reflectors located around 1 - 2 m distance from the

antenna phase center of the receiving antenna. An other explanation for this low

frequency component could be the atmospheric refraction errors, that produce a very

similar pattern. Therefore, with only one example, it is difficult to judge if this low

frequency residual error after correction should be considered a limitation of the

performances of the estimation algorithm or just an error due to atmospheric effects.

The auto correlation functions of o0Bs and EST-r shown in fig. A.1.8.c) are very

similar and recall the auto correlation of wide-band random noise (the envelope

decreases very rapidly, with a first zero crossing at z=1/(2B), were B is the bandwidth).

The cross correlation function between 0oBs and OESr is nearly symmetrical and is

well centered at zero, again confirming the strong affinity of the two time series

being compared. Additionally, the cross-spectral density and the coherence

function of fig. A.1.8.d) corroborate this conclusion. The two time series show a very

high coherence function (about 0.8) for frequencies between 0.001 Hz and 0.01 Hz.

Another good example of how well the estimation algorithm works in presence of

strong multipath is shown in fig. in fig. A.2.1 and A.2.2. The SNR shows

distinguished oscillations whenever the satellite PRN 20 is observed by the receiver

at an elevation 0 = 10' - 24' and azimuth 0 = 40 ° - 80°, at the time t= 7.0 - 7.5 104 sec.

The observed phase error determined from the measurement, 0OBs, and the

multipath phase error estimated from the SNR, •EST, are plotted and compared in

figures A.2.3, A.2.4 and A.2.7 (segment 2.b). The residual phase error given by the

difference of the two phase errors, ODIFF, is depicted in fig. A.2.8.a).

In the PSD of 40Bs and E)sr (fig. A.2.8.b) two main peaks at the same frequencies

are predominant , but a significant difference in amplitude can be noticed.

The auto and cross correlations of fig. A.2.8.c) deserve special attention. The auto

correlation function of a random process can be directly interpreted as a measure of

how well future values can be predicted from past observations. The key information

is how large in time is the envelope of the auto correlation function. An envelope

which decays rapidly to zero as in fig. A.1.8.c) resembles the auto correlation ofwide-

band random noise. If the auto correlation decays very rapidly, the knowledge of the

exact time history from zero to time t will not significantly help us to predict future

values beyond the very near future, i.e. beyond 1/(2B) past the end of the observed

record.

A very large envelope which does not decay rapidly, but which remains almost

constant over the near future (central peak 1/(2B) ), as in fig. A.2.8.c), resembles the

auto correlation of a sin/cos wave + random noise. This suggests that it is possible to

predict future values of the data, based on past observations, assuming that the data

remain stationary. This comparison of the auto correlations of the two time series

with the auto correlations of functions equal to the sum of a sinusoid and random

noise, confirms the influence on o0ss and 4~E of the multipath (sinusoidal in shape)

and of the contributions due to other GPS noises (random noise).

Auto and cross spectral power density and high values of the coherence function

(fig. A.2.8 d)), confirm the strong affinity of estimated multipath phase error and

observed phase error. As will be discussed in section 6.4, the multipath estimation

algorithm is very effective when multipath is the main source of phase error in the

GPS measurements, as for the receiver-satellite pair KKAU-PRN 20, segment 2.b.

This is confirmed by another interesting example relevant to KKAU -PRN 22,

segment #1. The SNR (fig. A.3.2) presents an evident sinusoidal pattern when

the satellite PRN 22 is at an elevation 0 = 100 - 30' and azimuth 4 = 50", at t=0.0 - 5.0

103 sec. The observed phase error determined from the measurement and the

multipath phase error estimated from the SNR are presented in figures A.3.3 and

A.3.4. The residual phase error 4 DIFF is plotted in fig. A.3.5.a). For the Power

Spectral Density (fig. A.3.5.b)), the auto and cross correlation (fig. A.3.5.c)), the auto

and cross spectral density and the coherence function (fig. A.3.5.d)) were

computed. Analogous observations than those for KKAU-PRN 20 can be applied.

The examples reported so far are relevant to cases in which a strong, clear

multipath phenomenon at frequencies between 0.001 Hz and 0.01 Hz is observed in

the phase residual. In these cases the estimation algorithm showed good

performances, as determined by spectral analysis. But how does the estimation

algorithm work in the presence of other sources of noise or in the presence of a

lower frequency multipath? To answer this question segment #2 of the data set

relevant to KKAU-PRN 22 was studied. In fig. A.3.6 the observed phase error

shows a low frequency component which is not present in the phase error estimated

from the SNR. As discussed above, this low frequency undulation might be caused

by multipath due to close reflectors or by atmospheric refraction. In fig. A.3.7 a)4 DIFF presents a large amplitude, and a low frequency component.

The PSD of fig. A.3.7b) shows the very different frequency content of the

observed and estimated phase error. In fig. A.3.7.c) the two auto correlation

functions show very different properties, and the correlation between the two series

presents low amplitude and evident asymmetry with respect to the zero. A very low

coherence function is found in fig. A.3.7.d) for all the frequency spectra.

5.3. .b) MANA (ROGUE SNR-8000)

When the SNR data relevant to the measurements acquired by MANA on June

10, 1995 were analyzed, large oscillations were observed every time a satellite was

found at low elevation angle and about 300" azimuth.

It appears evident in fig. A.4.1 and A.4.2 that the SNR exhibits large fluctuations

when the satellite PRN 26 is at 0 = 18" - 22* and 0 = 250* - 320', at t=1.0 - 2.0 104

sec. 0oBs and OEST are shown in figures A.4.3 and A.4.4. #DIFF, is plotted in fig.

A.4.5.a). Even though the large oscillations of 4oas are well matched by OESr, the

frequency content of the two time series is quite different. OBss presents a broader

spectra (Af=0.0003 - 0.003 Hz), while OEsr has a sharp peak at about 0.0015 Hz,

therefore a frequency component at 0.00085 Hz is still present in ODIFF, as shown in

fig A.4.5.b).

The auto and cross correlations are shown in fig. A.4.5.c). The coherence function

(fig. A.4.5.d) is about 0.6 in the interval of frequency between 0.001 and 0.01 Hz.

Large oscillations of the SNR were also observed for PRN 28 (fig. A.5.2) when the

satellite was at an elevation 0 = 15" - 35" and azimuth 0 = 250" - 310", at t=4.5 - 5.3 104

sec (fig. A.5.1). OoBs and OESr are presented in figures A.5.3 and A.5.8. ODIFF is

depicted in fig. A.5.9.a). Even though the statistical analysis shows a very strong

decrease of the phase error after the correction for multipath, the frequency content

of Ooss and OEST is quite different, and a large lower frequency component is found in

vDIFF, as observed in fig. A.5.9.b).

The auto and cross correlations of fig. A.5.9.c) suggest a predominance of random

noise on the multipath effect in the phase error. The coherence function (fig.

A.5.9.d) is close to 0.7 in the interval of frequency between 0.001 and 0.01 Hz.

5.3.1.c) Discussion and Comparison

The previous analysis shows that the multipath frequency for KKAU is usually

higher than the one observed for MANA.

In figures A.1.8.b) , A.2.8.b) and A.3.5.b) it is evident that the multipath

frequency for KKAU is usually in the range 0.002-0.004 Hz.

For MANA, the multipath frequency is lower than for KKAU and it is in the range

0.0009 - 0.0010 Hz. This indicates that the reflecting surface producing the

multipath in this case (MANA) is closer to the receiving antenna and its effect is

also more intense. The relationship between the distance of the reflector and the

multipath frequency is given in [2.17].

5.3.2 Stations 0036 and 0028 (TRIMBLE 4000SSE)

5.3.2.a) 0036: Dual-band processing

Some a priori information relevant to this site were available and were used to

better interpret the results of the spectral and statistical analyses. The geometry of

the surroundings of the receiver 0036 is depicted in figure 5.1, where the incoming

signal from the satellite PRN 09, located at about 15" elevation and 45' azimuth,reaches the receiver after multiple reflections. The SNR relevant to this satellite-

receiver pair is plotted in fig. A.6.4. The SNR is affected by very distinct largeoscillations when the satellite is at an elevation 0 = 14" - 22* and azimuth < = 40* - 50",

at t=7.3 - 7.5 104 sec (fig. A.6.3).

OBs and OEsr are compared in figures A.6.5 and A.6.6. The difference between

the two phase errors is plotted in fig. A.6.7.a).

The PSD of 0oBs and OEsr (fig. A.6.7.b) exhibit one narrow distinct peak at about

0.001 Hz. This information suggests that in this case the multipath is not produced

by a complex scattering from several reflectors, but from one distinct reflector

producing one distinct frequency component.

Because of the coherence of the two time series, the frequency content of ODIFF

does not present any strong predominant frequencies. This implies that the main

contribution to the phase error is due to multipath and is filtered out by the

correction. The remaining phase error is due to the other sources of GPS random

noise, which cannot be corrected with this method.

The auto correlation functions of 0oBs and OEST shown in fig. A.6.7.c) present very

interesting patterns. The envelope amplitude diminishes slowly and recalls the auto

correlation of a narrow-band random noise, where the first zero crossing is at t=1/B

(B is assumed small). The bandwidth is smaller in EsTr, causing its auto correlation

function to decay slower than the auto correlation of OoBs. It can be concluded that

Oos contains more random noise and a larger bandwidth scattering.

The cross-spectral density and the coherence function of fig. A.6.7.d) reinforce

the conclusion that a distinct frequency is dominant in the signal, with very narrow

bandwidth. The two time series show a high coherence function (about 0.7) for

frequencies between 0.001 Hz and 0.01 Hz.

Another example of strong multipath is shown in fig. A.8.5 and A.8.6. The SNR

relevant to the satellite PRN 25 shows large oscillations when the satellite was at an

elevation 0 = 15' - 20' and azimuth 4 = 164' - 168', at t= 7.5 - 7.7 104 sec. The

observed phase error determined from the measurement and the multipath phase

error estimated from the SNR are plotted and compared in figure A.8.7 (segment

#1). oDIFF is shown in fig. A.8.8.a). In this case the oscillations are not as distinct as

for PRN 09.

The PSD of 0oBs (fig. A.8.8.b) show two narrow peaks, respectively, at frequencies

of 0.001 Hz and 0.002 Hz. OEsr presents a narrow main peak at 0.002 Hz and a broad

band low frequency peak between 0.0001 Hz and 0.0005 Hz. As a result of this

spectral difference, the PSD of ODIFF has a predominant low frequency spectral

content.

The auto and cross correlations of fig. A.8.8.c) present an envelope rapidlydecreasing to zero, as for wide band random noise. This suggests that the multiplephase error does not come from a single reflector, as in the previous case for PRN09, but might be due to a more complex scattering phenomenon from close anddistant surfaces. The cross-spectral density and the coherence function of fig.A.8.8.d) reinforce this conclusion. The two time series show a coherence functionof about 0.6 for frequencies between 0.001 Hz and 0.01 Hz.

An interesting example where there is a noticeble difference of amplitudebetween 4os and 4 EST, rather than of frequency content, is given by LIGO 0036,PRN 15. (segment #4). ODIFF is computed in fig. A.7.10.a). The observed phase

residual presents small oscillations similar to the ones found in the estimated phaseerror, but with a different amplitude: 0oss is always negative while ESTr is shiftedupward and presents some positive and negative values.

The Power Spectra Density (PSD) of this segment of data is shown in fig.A.7.10.b). The PSD of OBs and EsrT are consistent at high frequencies. They bothexhibit one peak close to 0.001 Hz.

The auto correlation functions in fig. A.7.10.c) are very different and the crosscorrelation is asymmetric and small in amplitude.

5.3.2.b) 0036 and 0028: Single Differences for short-baseline LI and L2

As discussed above, for short baselines the ionospheric effects can be filteredusing single differencing. In this case it is possible to study the effect of multipathat each of the two GPS frequencies and the performance of the estimation algorithmfor LI and L2.

In this section we show the results of the analysis of LI and Lz separately, as twoindependent observables. l1OBS, slEST, and 4 1DIFF indicate respectively, the

observed phase residual, the multipath phase error and their difference, respectively,for LI.

OloBs and IlEST are compared in fig. A.9.1 and A.9 2. I1DIFF is shown in fig.A.9.3.a). PSD of loBs and O'EST are presented in fig. A.9.3.b).

The spectral content of 01OBs and $IEST is very similar at higher frequencies,showing a predominant peak at 0.002 Hz, but does not agree at lower frequencies.Therefore, the PSD of OIDIFF shows a spectral content only at lower frequencies(below 0.001 Hz).

The auto correlation of ~'EST (fig. A.9.3.c) recalls the one of a narrow-bandrandom noise. The cross correlation Roe is well centered but slightly asymmetric. Agood coherence is found at f=0.001 Hz.-0.01 Hz (fig. A.9.3.d). In this case thefrequency content matches very well, but the shift in amplitude causes (1DIFF tO staylarge also after the correction. A very different result is obtained for L2 (fig. A.9.4and A.9 5), where the amplitude of 02DIFF is well reduced (fig. A.9.6.b) ), eventhough a low coherence is observed (fig. A.9.6.d) ).

5.3.3 COSE and GS29

5.3.3.a) COSE (TRIMBLE 4000SSE)

The data considered for this analysis were acquired on January 23, 1997 using aTrimble antenna . Any time a satellite was at a low elevation angle ( 0 = 10" - 20" )and azimuth 0 = 50' - 70", the SNR showed large oscillations at LI and L2. Anexample of the multipath phenomenon occurring in proximity of COSE is providedin fig. A.11.1 and A.11.2.

The satellite PRN 25 passed through the critical region in the field of view ofCOSE at t=5.6 - 6.2 104 sec. OBas and ES~rare plotted and compared in figure A. 11.3(segment #3). ODIFF iS computed in fig. A.11.6.a).

The observed phase error presents only one very large oscillation at the end of thesegment, probably due to reflections from the ground because the antenna waslocated on a large slope. The satellite was setting and this strong reflection cantherefore take place at a very low elevation angle (0 = 10").

The Power Spectral Density of this segment of data is shown in fig. A.11.6.b).The PSD of 4OBs and OEST are very consistent for amplitude and frequency content.

They both exhibit large peaks at the same frequency, about 0.001 Hz, but with verydifferent amplitudes. This is the reason why ODIFF still carries a considerable

frequency content. In this particular case, it is not the frequency content, but the

amplitude of the multipath phase error estimated by the algorithm that produced the

critical result. An overestimation of the amplitude of the oscillation increases the

total phase error after the multipath correction.The auto correlation functions of Oos and EST shown in fig. A.11.6.c) recall the

auto correlation of a wide-band random noise. The cross-spectral density of fig.A.11.8.d) confirm the previous results of the spectral analysis. The two time seriesshow a very high coherence function (about 0.8) for frequencies between 0.0005 Hzand 0.01 Hz.

An interesting case to study is COSE PRN 01, segment lb., In chapter 3 thetechnique for the multipath estimation was described. When the fit of the multipathmodel and the SNR curve is performed, some problems can rise, due to the methodused for the fit (section 3.3.3). ODIFF presents sudden changes of sign deriving from

mESr (fig. A.9.6.a)). Correlation and spectral analysis show a poor agreement between

O0sS and OEsr.

5.3.3.b) GS29 (ASHTECH Z-XII3)

The same set of GPS measurements discussed in section 5.3.3.a) were repeatedby using an Ashtech antenna, placed at the same location of COSE, the day after (onJanuary 24, 1997). As for COSE, the satellite PRN 25 was considered, and the

analysis on the station GS29 was performed (fig. A.14.1 and A.14.2 )

O0Bs and OEsr are shown in figure A.14.3 and A.14.4 (segment #3). ODIFF iscomputed in fig. A.14.7.a). The observed phase error presents only one very large

oscillation at the end of the segment, as was observed for COSE.The PSD of this segment of data is shown in fig. A.14.7.b). The PSD of o0s and

mEST are very consistent for amplitude and frequency content. They both exhibit onelarge peak of similar amplitude at about 0.001 Hz. DIFF does not present a

considerable frequency content, because in this case the frequency content and the

amplitude of the multipath phase error estimated by the algorithm match very well

the observed phase error. Therefore, as will be discussed in the statistical analysis,the application of the algorithm produces a strong decrease of the phase error afterthe multipath correction.

The auto correlation functions of 04s and Omr presented in fig. A.14.7.c) is

similar to those found for wide-band random noise. The cross-spectral density of fig.A.14.7.d) confirms the previous results of the spectral analysis. The two time seriesshow a very high coherence function (about 0.8) for frequencies close to 0.002 Hz.

In the conclusion of section 5.3.3.a) and 5.3.3.b), it was found that the estimationalgorithm applied to data acquired at the same location and the same time of the daywith two different antennas presented different performances. The algorithm seemsto work better for Ashtech antennas. However, because the weather conditionsduring the two successive days were not the same, it is difficult to assess if the resultsare actually due to the antenna type, or to the higher multipath effect observed on rainydays. We already noticed that the multipath estimation algorithm is very efficientwhen strong multipath is observed, especially if it is predominant with respect to otherkinds of noise. It is therefore possible that a different wetness of the ground,producing a higher reflectivity of the reflecting surfaces, might have caused a better

performance of the algorithm. One way to answer this question is to consider two sets

of measurements acquired with the same antenna, during these two days of

observations and compare the results. This is done in the next section, forCOSO(Ashtech).

5.3.3.c) COSO (ASHTECH Z-XII3)

For this analysis we selected the measurements relevant to the satellite PRN 30,because of the large oscillations observed in SNR and 0oBs (fig. A.15.1 and A.15.2).The phase residual DIFF is shown in fig. A.15.3.a). The PSD of o0Bs and rESr (fig.A.15.3.b) ) present the same peaks at 0.0005 Hz, but 90Bs also has peaks at lower

and higher frequencies (0.0001 and 0.001), which are found again in the PSD of

'DIFF.

The correlation of the two series (fig. A.15.3.c) ) as well as the coherence (fig.

A.15.3.d) ) is very poor.

The same measurement was repeated the next day, in weather conditions favorable

for strong multipath (rainy day). The phase residuals relevant to these measurements

are plotted in fig. A.16.1 and A.16.2. The PSD of 0 Bs and 4ESr (fig. A.16.3.b) )

present a very similar spectral content, showing a predominant peak at 0.0004 Hz.

The correlation (fig. A.16.3.c) ) and coherence (fig. A.16.3.d) ) are higher than in

figures A.16.3.c) ) and (fig. A.16.3.d) ). This result confirms that the wetness of the

ground increases the multipath effects, and therefore the performance of the

estimation algorithm improves.

5.4 Multipath Estimation and Results of theStatistical Analysis

The following is a summary of the results obtained from the statistical analysis of

the GPS phase residuals, described in Chapter 4. The study focused on 6 GPS

stations, MANA, KKAU, 0028, 0036, COSE and GS29, because of their strong

multipath environment. The analysis includes 42 sets of data, collected and sorted

in tables B.1.a) and b) through B.5.a) and b).

The variance of the observed phase residual is referred to as GOBS 2 , and denotes

the total phase error due to the combined effects of different sources of noise for

the GPS carrier phase observable. ausr 2 is the variance of the estimate of the

multipath phase error retrieved by using the SNR information. The difference

between oBs 2 and GOr 2 is the corrected phase error, and its variance is denoted

with ODIFF2 . The difference of variance of the phase error before and after the

correction for multipath was computed along with the statistical uncertainty of the

estimate of the change. This computation allows us to determine how well the

correction improves the GPS positioning by quantitative means.

Whenever a negative value is obtained for (GooBs 2 - GDInr2), the correction for the

multipath phase error does not reduce the variance of the total phase error. Apositive value, on the other hand, would imply a decrease of the variance of the GPS

phase error, and, thus, an improvement in the final GPS positioning. When such apositive value is obtained, the percentage decrease of variance was computed, tomake it easier to quantify the improvement of the variance after correction.

There is a noticeable decrease of the variance after the multipath correction anytime the variance of the "true" multipath noise oMPN 2 is higher or at least comparableto the variance of the GPS measurement noise, oMN2, due to other sources of noise

different from multipath. In other words, the algorithm for multipath phase errorestimation shows very good performance whenever the multipath effect is the mainsource of phase error. Good examples of this observation are given in MANA 26 lband MANA 28 2a (Table B.l.a and b), KKAU 16 2c (Table B.2.a and b), LIGO0028-0038 09 1 (Table B.3.a and b) and GS29 25 3 (Table B.5.a and b). In thesecases the decrease of variance of the phase error after correction is more than 35%.

The value yEN 2 is a measure of the error due to the estimation process and gives

information about the accuracy of the procedure for the phase error estimation.The examples previously discussed present a small GEN2 value with respect to the

multipath noise variance oMPN2. This result confirms that the estimation algorithm is

most accurate when a strong multipath is present.However, an exception to the previous cases is COSE 01 ic (Table B.4.a and b), a

measurement performed with a Trimble antenna. Even though the multipath noisevariance is more than 3 times larger than aMN 2, the multipath estimation noise is ofthe same order of magnitude as oMPN 2 and the decrease of variance after correction

is only 4%. This measurement was repeated the following day , in rainy weather,exactly at the same location, using an Ashtech antenna (GS29 01). It turns out thatOMN2 drops to 1/10 the value of ouCPN 2 and the decrease of variance after correction

improves to 16 % (Table B.5.a and b).Good examples of poor multipath in an otherwise very noisy measurement

( oMPN2 << MN 2 ) are MANA 26 2c (Table B.l.a and b) , KKAU 22 2 (Table B.2.a

and b) and GS29 25 1 (Table B.5.a and b). In these cases there is no decrease ofvariance after correction and the estimation noise variance aEN2 is larger than themultipath noise variance ouPN2 itself.

Chapter 6

Conclusions

The algorithm for the estimation of the GPS multipath phase error presented in

this thesis was applied and analyzed, to test its performance and limits. The

estimated multipath phase error and the observed phase residual were compared by

spectral and statistical analysis.

In most of the cases analyzed, a broad-band coherence function between the

observed phase error and the estimated multipath phase error was found in presence

of strong multipath. This suggests that the effects of multiple reflectors are correctly

estimated by the proposed algorithm. In other words the technique of estimating

each multipath phase error iteratively from the spectral analysis of the SNR and of

adding each contribution to obtain the composite value, produces a correct

estimation of the total multipath phase error.

In particular, the set of data which show the highest coherence (MANA and

KKAU and LIGO 0036) have multipath frequencies between 0.001 and 0.01 Hz.

Because the multipath frequency depends on the distance of the receiving antenna

from the reflecting surface, knowing the elevation angle of the satellite and its

variation with time, we can derive the distance of the reflecting object. The spectral

analysis suggests that the estimation algorithm presents good performances for

reflectors located at distances between 5.50 m and 55.0 m from the receiving

antenna, for an elevation angle of 10* and a rate of change of the elevation angle of

0.1 mrad/sec. The high coherence is confirmed by the statistical analysis, which

shows a significant decrease of the RMS of the phase residual after the multipath

correction.

When the multipath effect is due to reflections from the ground (about 1.5 - 2.0

m) the multipath frequencies are lower (COSE and GS29). At lower frequencies it

was found that the algorithm performed better for data sets acquired in the same

location by an Ashtech receiver (GS29, January 24,1997), rather than a Trimble

(COSE, January 23,1997). This result can be due to the different receiver types, the

different antenna gains or/and the weather conditions.

As explained in section 2.3, Trimble and Ashtech receivers use different

techniques for the signal processing of L2 in presence of antispoofing. Trimble

receivers cross correlate L2 with LI and the available SNR limits the bandwidth of

the L2 carrier. A narrower bandwidth corresponds to a longer integration time,which makes it more difficult to track large oscillations of the SNR, especially at low

frequencies. Ashtech receivers use the Z-tracking technique, which provides a

better SNR compared to other techniques. Because the estimation algorithm

proposed in this thesis manipulates the SNR information to retrieve the multipath

phase error, the errors introduced by each receiver in the determination of the SNR

strongly influence the performance of the algorithm.

GPS measurements acquired by the station COSO in the same days, one sunny

and dry (January, 23 1997), the other rainy and gray Ganuary, 24 1997), suggests that

also the weather conditions considerably change the performance of the algorithm.

A higher water content in the ground increases its reflection coefficient, causing the

multipath effects to be stronger in rainy more than in dry weather. On the other

hand, the performance of the algorithm is good when strong multipath is observed,because the main contribution to the observed phase residual is due to the multipath

phase error. In other words, when multipath is the main error contribution, the

estimated multipath phase error is highly correlated to the total observed phase

residual.

Low frequency oscillations of the SNR might also be produced by the ionosphere

(scintillation) but these effects are likely to be small. Low frequency SNR variations

are most likely to be due to the gain pattern of the antenna, especially for the

Trimble antennas. These antennas are known to have azimuthally dependent gainpatterns, which are not accounted for in the estimation algorithm. The algorithmmight interpret these oscillations as multipath, and, therefore, estimate a false phaseerror.

We already pointed out that different antennas might influence the performancesof the algorithm. The Dorne-Margolin antennas have a higher gain pattern at verylow elevation angles with respect Trimble antennas: this suggests that moremultipath contributions from lower elevation angles are received with a higheramplitude.

The study of short baselines (LIGO 0036-0028, PRN 09) allows as to consider thesingle differences for LI and L2 separately: the results of the spectral analysis show ahigh broad-band coherence for the multipath phase error at LI but a very lowcoherence at L2. However, in both cases the multipath estimation produces adecrease of the RMS of the total phase error after correction, as it is shown by theresults of the statistical analysis. The best performance in terms of both, spectraland statistical analysis was obtained using the estimation algorithm for the dual-frequency mode (LCEST). Because the square root of the PSD (power spectraldensity) of the observed phase error is almost equal to the sum of the square root ofthe estimated phase error and the difference between observed and estimated forthe most of the cases, we can deduce that the two curves we are comparing(LCLOBS and LC_EST) are in phase, and there is only a difference in amplitudebetween them. This is consistent with having a very high correlation function andwith L2 having the correct phase but the wrong amplitude.

One problem of the estimation algorithm which is important to mention is relatedto the sign of the phase error. As it was pointed out in chapter 2, the same SNR canbe due to opposite values of the phase error, (positive and negative). Therefore, thesign of the phase error cannot be uniquely determined. In some cases thisindetermination might cause an abrupt change of the sign of the estimated phaseerror (COSE PRN 01, segment lb), producing a considerable degradation of theperformances of the estimation procedure.

In summary, the proposed algorithm shows good results when multipath is themain contribution to the total phase error and it frequency is in the range 0.001-0.01Hz. At lower frequencies, the performance depends on the receiver-antenna type

and the weather conditions. The sign of the phase error and the nature of the lowfrequency oscillations are critical for the results of the estimation.

References

Axelrad, P., C. J. Comp and P. F. MacDoran, "Use of Signal-to-noise Ratio for

Multipath Error: Correction in GPS Differential Phase Measurements:

Metodology and Experimental Results", Proceedings of ION GPS-94,

September 1994.

Balanis, C.A., 1982, Antenna theory: analysis and design. New York: Harper and

Row series in electrical engineering.

Balanis, C.A., 1989, Advanced Engineering Electromagnetics, John Wiley & Sons

Becker, D., P. Hartl and K.-H. Thiel, A special method of managing multipath

effects,

Bendat, J.S. and A.G. Piersal, Engineering Applications of Correlation and Spectral

Analysis, John Wiley&Sons, Inc., 1993.

Bletzacker, F. " Reduction of Multipath Contamination in a Geodetic GPS

Receiver," Proceedings of the First International Symposium on Precise

Positioning with the Global Positioning System, U.S., Department of Commerce,

National Oceanic and Atmispheric Administration, Rockville, MD, pp. 413-422,

April 1985.

Blewitt, G., "Advances in Global Positioning System Technology for Geodynamic

Investigations: 1978-1992" in Contributions of Space Geodesy to Geodynamics:

Technology, Geodyn. Ser., Vol.25, edited by D.E. Smith and D.L. Turdotte,

pp.195-213, AGU, Washington, DC, 1993.

Blewitt, G., "Carrier Phase Ambiguity Resolution for the Global Positioning System

Applied to Geodetic Baselines up to 2000 km", Journal of Geophysical

Research, Vol. 94, No. B8, pp 10187-10203, August io, 1989.

Bock, Y., Gourevitch, S.A., Counselman III C.C., King R. W., and Abbot R.I., "

Interferometric analysis of GPS phase observations, Manus. Geod., II, 282-288,

1986.

Braasch, M., " On the Characterization of Multipath in Satellite-Based Precision

Approach and Landing Systems", Ph.D. Dissertation, Deparment of Eleectrical

Engineering and Computer Engineering, Ohio University, Athens, OH, June

1992.

Braasch, M., "Isolation of GPS Multipath and Receiver Tracking Errors,"

Proceedings of the ION National Technical Meeting, San Diego, CA, Institute

of Navigation, Washington, DC, pp. 511-521, Jan. 1994.

Breeuwer, E., "Modeling and Measuring GPS Multipath Effects," Master's Thesis,

Department od Electrical Engineering, Delft University of Technology, Delft,

The Netherlands, January 1992.

Clark, T., "GPS antennas: De-mystivying Multipath", NASA Goddard International

Memorandum, March 5, 1992.

Collin, R.E., Zucker F.J., Antenna Theory, McGraw-Hill, 1969.

Counselman, C., and Gourevitch, S., "Miniature Interferometer Terminals for Earth

Surveying: Anbiguity and Multipath with Global Positioning System," IEEE

Transaction on Geoscience and Remote Sensing, Vol. GE-I9, No.4, pp. 244-252,

I98I.

Counselman, C., "Miniature Interferometer Terminals for Earth Surveying (MITES):

Geodetic Results and Multipath Effects," Digest of the International

Geoscience and Remote Sensing Symposium, Washington, DC, Institute of

Electrical and Electronics Engineers, New York, pp 219-224, June 1981.

Dong, D., Bock Y., " Global Positioning System Network Analysis With Phase

Ambiguity Resolution Applied to Crustal Deformation Studies in California.

Elosegui, P., J. L. Davis, R. T. K. Jaldehag, J. M. Johansson, A. E. Niell and I. I.

Shapiro, "Geodesy using Global Positioning Systems: The effects of signal

scattering on estimates of site position", Journal of Geophysical Research, Vol.

Ioo, No. B7 , pp. 9921-9934, 1995.

Evans, A., "Comparison of GPS pseudorange and Biased Doppler Range

Measurements to Demonstrate Signal Multipath Effects," Proceedings of the

International Telemetering Conference, Las Vegas, NV, Instrument Society of

America, Research triangle Park, NC, pp.795-8 01, Oct. 1986

Georgiadou, Y. and Kleusberg, A., "On Carrier Signal Multipath Effects in Relative

GPS Positioning" Manuscritpa Geodetica, Vol.i3, pp. 172-179, 1988.

Hajj, G. A., The Multipath Simulator: A Tool Toward Controlling Multipath, in

Proceedings of the 2nd Symposium on GPS Applications in Space, Hanscom

AFB, MA, 1990.

Herring, T.A., "Precision of Vertical Position Estimates from Very Long Baseline

Interferometry", Journal of Geophysical Research, Vol. 91, 9177-9182, 1986.

Herring, T.A., "Precision and Accuracy in Intercontinental Distance

Determinations Using Radio Interferometry", Ph.D. Dissertation, Department of

Earth and Planeraty Sciences, at the Massachussets Institute of Technology, July,

1983.

King, R.W., and Y. Block, Documentation for the MIT GPS analysis software:

GAMIT, Mass. Inst. of Technology, Cambridge, 1993.

Kong, J.A., Electromagnetic Wave Theory, John Wiley & Sons, 1990.

Kee, C. and B. W. parkinson, Calibration of Multipath Errors on GPS Pseudorange

Measurments,

Kraus, J.D., "Electromagnetics", McGraw-Hill Inc., 1992.

Meehan, T., and Young, L., "On-Receiver Signal Processing for GPS Multipath

Reduction," Proceedings of the 6th International Geodetic Symposium on

Satellite Positioning, Columbus, OH, Defense Mapping Agency and the Ohio

State University, Columbus, OH, pp. 200-208, March 1992.

Oppenheim, A.V., R.W. Schafer, Discrete-Time Signal Processing, Prentice-Hall

Inc., Englewood Cliffs, NewJersey 07632, 1989.

Parkinson, B., Spilker Jr, J., "Global Positioning System: Theory and Applications,"

Vol.I and Vol. II, Volume 163 and Volume 164, Progress in Astronautics and

Aeronautics, Published by the American Institute of Astronautics and

Aeronautics, Inc. 370 L"Enfant Promenade, SW, Washington, DC 20024-2518.

Schupler, B. R. and R. L. Allshouse, "Signal Characteristics of GPS User Antennas",

Navigation: Journal of the Institute of Navigation, VoL 41, No.3, pp 277-295, 1994.

Schupler, B. R., R. L. Allshouse and T. A. Clark, Signal Characteristics of GPS User

Antennas, Navigation, Vol. 41, 277-295, 1994.

Sennott, J., and Pietraszewski, d., "Experimental Measurements and

Characterization of Ionospheric and Multipath Errors in Differential

GPS,"Navigation, Vol. 34, No.2, pp.160-173, 1987.

Spilker, J.J., "GPS Signal Structure and Performance Characteristics", J. of Inst.

Navig., VoL 25(2), pp. 121-146, 1978.

Tranquilla, J., and Carr, J., "GPS Multipath Field Observations at Land and Water

Sites", Navigation, Vol. 37, No.4, pp.393-414, 1991.

Tranquilla, J.M., Carr, J.P., Al Rizzo, H.M., "Analysis of a Choke ring groundplane

for multipath control in Global Positioning System (GPS) applications" , IEEE

Trans. Antennas Propag., Vol. 42, pp 905-911, 1994.

Van Dam, T.M., T.A. Herring, "Detection of atmospheric pressure loading using

very long baseline interferometry measurments", Journal of Geophysical

Research, Vol. 99, No. B3, pp. 4505-4517, March io, 1994.

Van Nee, R., "Multipath Effects on GPS Code Phase Measurements," Proceedings

of ION GPS-9I, Albuquerque, NM, Institute of Navigation, Eashington, DC,

Sept. 1991, pp. 915-924.

Van Nee, R., "Spread Spectrum Code and Carrier Synchronization Errors Caused by

Multipath and Interference," IEEE Transactions on Aerospace and Electronic

Systems, Vol. 29, No. 4, PP- 1359-1365, 1993.

White, P.H., "Cross-Correlation In Structural Systems: Dispersive ans Non-

Dispersive Waves", Journal of the Acoustic Society of America, Vol. 45, No. 5, pp.

1118, May 1969.

Young, L.E., Neilan R.E., and F.R. Bletzacher, "GPS Satellite Multipath: An

Experimental Investigation" Proceedings of the First Symposium on Precise

Positioning With the Global Positioning System, National Oceanic and

Atmospheric Administration, Rockville, Maryland, pp.423-432, 1985.

Appendix A

90 9060

. ., 30

21

240 300270

GPS DATA: receiver location: CENTRAL ASIA acquisition date: 10 6 1995

station: KKAU satellite: PRN 16

Time (sec)

Fig. A.1.1 :

40C

30C

200

100

0

station: KKAU satellite: PRN 16

I·I, - , !

0

x 104

1 2 3 4 5Time (sec)

Satellite visibility chart for PRN 16 (skymap).Elevation and azimuth of PRN 16 with respect tothe station KKAU.

90

1

x 10'

KKAU PRN 16 10 6 1995

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5x 10

Signal to Noise Ratio for L1 and L2

0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5Time (sec) v n4

Fig. A.1.2 : Station: KKAU - Satellite: PRN 16 -Data acquisition date 10 6 1995.

Signal-to-Noise-Ratio (SNR) for Li and L2.

80

-c60

o40

_ 20Uj

g I I I I

20

_I · · · ·

I

I ·

· ·

I r I

........ ..--- · ·----.-

1 I

I I I I I I I I I.. ...·........ .·..... ·.........·... -! .·.... ~ .......~t I | |

,. . .

I

A III,

GPS "OBSERVED" Phase Residuals for: KKAU PRN 16 - ASIA 1995 6 10

I- I

| ... I .• : :-.... . .... -..'- ' ." ""_. ........ ....... ......... !. ...... ...• ii•' :I .. .. i ........ ....... .. ..- ; ..-... .: ::. ...... ., .. . ... ..... ..... ...... .... .: .- -.. .

." ..." ."1" .. . .. . ." ......... ........... ........... .........•; ·

I " I·-- · ·- · · ·I · · · ·-- · ·: I I ..-

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5GPS "ESTIMATED" Phase Residuals computed from the analysis of SNR variation x10

........... ....................... . ... ........................ ...

0.5 1 1.5 2 2.5 3 3.5 4 4.5 5Comparison LC OBSERVED vs LC ESTIMATED x10

..... ................. .. . . ....................... ... .... ...... ..

......1: ~·. ,..... .................. ...I- · - I-r Ir- ..... i .............. .......... .......... .......... ........... ........ ......... ......

0.5 1 1.5 2 2.5Time (sec)

3 3.5 4 4.5 5

x 104

-III

Fig. A.1.3 : Station: KKAU - Satellite: PRN 16Data acquisition date 10 6 1995The observed phase residual (LCOBS) is compared with themultipath phase error estimated from the SNR (LC..EST).Unit: [cycles).

92

0.20.1

0

-0.1-0.2

0.20.1

0

-0.1-0.2

0.20.1

0-0.1-0.2

ii, i i i ; ; ; ; ; (

-

-

-

-

-

KKAU PRN 16 - ASIA 1995 6 10

3 3.2 3.4 3.6 3.8 4 4.2 4.4 4.6 4.8 5Time (sec) x 10'

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Fig. A.1.8.a) : KKAU - PRN 16 (10 6 1995) - [segment 2c]

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Unit: [cycles]

116

U.2

0.1

w

0

0 -0.1

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7

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"RESIDUAL" = difference LC Observed - LC Estimated

7 7.05 7.1 7.15 7.2 7.25 7.3 7.35 7.4 7.45Time (sec)

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x 104

o = LC OBSERVED * = LC ESTIMATED

7 7.05 7.1 7.15 7.2 7.25 7.3 7.35 7.4 7.45 7.5Time (sec) x 10,

Fig. A.2.8.a) KKAU - PRN 20 (10 6 1995) - [segment 2b]Phase residual LC.DIFF, determined as the differencebetween LCOBS and LCEST.Unit: [cycles]

117

0.1

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KKAU - PRN 20 (10 6 1995) - [segment 2b]Auto Correlation of LC..OBS (Ro,) and LC_EST (Ree).Cross Correlation between them (Roe)

Unit: [cycles] 2

119

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SI I I I I I I I

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receiver location: CENTRAL ASIA acquisition date: 10 6 1995

station: KKAU satellite: PRN 22 station: KKAU satellite: PRN 2240C

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Satellite visibility chart for PRN 22 (skymap).Elevation and azimuth of PRN 22 with respect tothe station KKAU

121

1

GPS DATA:

Fig. A.3.1 :

KKAU PRN 22 10 6 1995....... I

0 1 2 3 4 5 6 7 8 9x 10

Signal to Noise Ratio for L1 and L2

0 1 2 3 4 5 6 7 8

4 5Time (sec)

Fig. A.3.2 :

9

x 10'

Station: KKAU - Satellite: PRN 22Data acquisition date 10 6 1995Signal-to-Noise-Ratio (SNR) for LI and L2.

122

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80

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GPS "OBSERVED" Phase Residuals for: KKAU PRN 22 - ASIA 1995 6 10

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1 2 3 4 5 6 7 8Time (sec)

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x 10'

Station: KKAU - Satellite: PRN 22Data acquisition date 10 6 1995The observed phase residual (LCOBS) is compared with themultipath phase error estimated from the SNR (LC..EST).Unit: [cycles]

123

ft ^

C 0.1

Ca,0OU -0.1

-0.2-0.2 0

Fig. A.3.3 :

KKAU PRN 22 - ASIA 1995 6 10 :segment #1

500 1000 1500 2000 2500 3000 3500Time (sec)

1000 1500 2000Time (sec)

2500 3000 3500

Station: KKAU - Satellite: PRN 22

Data acquisition date 10 6 1995

LC_OBS and LCEST compared for t=0.0 - 3.5 10 3 sec

Unit: [cycles)

124

-0.1

-0.2

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I B I

1* .1.

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Fig. A.3.4 :

"RESIDUAL" = difference LC Observed - LC Estimated

1000 1500

o = LC OBSERVE

2000 2500Time (sec)

D * = LC ESTIMATED

3000 3500 4000

500 1000 1500 2000 2500 3000 3500Time (sec)

4000

Fig. A.3.5.a) : KKAU - PRN 22 (10 6 1995) - [segment #1]

Phase residual LCLDIFF, determined as the difference

between LCOBS and LCEST.

Unit: [cycles]

125

0.15

0.1

0.05

0

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1000 2000 3000 4000

1000 2000 3000 4000Time [sec]

Fig. A.3.5.b) KKAU - PRN 22 (10 6 1995) - [segment #1]

PSD of LC.OBS, LCEST and LC..DIFF.

Unit: [cycles] 2

126

0.2

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CROSS-CORRELATION between LC OBS and LC EST

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Fig. A.3.5.c)

time delay : Tau1000

(sec)2000 3000 404

00

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KKAU - PRN 22 (10 6 1995) - [segment #1]Auto Correlation of LCOBS (Roo) and LC_EST (Ree).Cross Correlation between them (Roe)

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Time (sec)

4.7Time (sec)

x 104

4.8

x 104

Station: KKAU - Satellite: PRN 22Data acquisition date 10 6 1995LC.OBS and LCEST compared for t=4.3 - 5.1 10 4 secUnit: [cycles)

129

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4.7Time (sec)

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Fig. A.3.7.a) KKAU - PRN 22 (10 6 1995) - [segment #2]Phase residual LC..DIFF, determined as the differencebetween LC..OBS and LC.EST.Unit: [cycles]

130

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CROSS-CORRELATION between LC OBS and LC EST

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time delay : Tau (sec)2000 4000 6000 8000

KKAU - PRN 22 (10 6 1995) - [segment #2]Auto Correlation of LC_..OBS (Roo) and LC_EST (R,).Cross Correlation between them (R0e)Unit: [cycles] 2

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Station: KKAU -Satellite: PRN 22Data acquisition date 10 6 1995LC_OBS and LC__EST compared for t=7.2 - 8.7 10 4 secUnit: [cycles]

134

0.2

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"RESIDUAL" = difference LC Observed - LC Estimated

7.2 7.3 7.4 7.5 7.6 7.7Time (sec)

o = LC OBSERVED * - LC ESTIMATED

7.3 7.4 7.5 7.6 7.7Time (sec)

7.8

x 10'

Fig. A.3.9.a) : KKAU - PRN 22 (10 6 1995) - [segment #3.a]Phase residual LC_.DIFF, determined as the differencebetween LC.OBS and LCJEST.Unit: [cycles]

135

7.8x 104

0.05

0

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'-1

: segment #3.a)

7.27.2

"RESIDUAL" - difference LC Observed - LC Estimated

7.8 7.85 7.9 7.95 8 8.05 8.1 8.15Time (sec)

7.8 7.85 7.9 7.95 8 8.05 8.1 8.15Time (sec)

Fig. A.3.10.a) : KKAU - PRN 22 (10 6 1995) - [segment #3.b]Phase residual LCDIFF, determined as the difference

between LCOBS and LC.EST.

Unit: [cycles]

136

8.2x 10'

8.2x 104

: segment #3.b)

"RESIDUAL" = difference LC Observed - LC Estimated

Time (sec) x 10

8.2 8.25 8.3 8.35 8.4 8.45 8.5 8.55 8.6 8.ETime (sec) x 10'

Fig. A.3.11.a) KKAU - PRN 22 (10 6 1995) - [segment #3.c]Phase residual LC-DIFF, determined as the differencebetween LCOBS and LC.EST.Unit: [cycles]

137

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5.25 5.3 5.35Time (sec)

5.4 5.45

MANA PRN 28 : o = LC OBSERVED * = LC ESTIMATED

5.2 5.25 5.3 5.35 5.4 5.45 5.5Time (sec) x 10'

Fig. A.5.10.a) MANA - PRN 28 (10 6 1995) - [segment 2.b]Phase residual LC.DIFF, determined as the differencebetween LC.OBS and LCEST.Unit: [cycles]

184

0.1

A A

0.0

-0.0

-0.1

I I I I I

5.2 5.5x 10'

i I

: segment 2.b)

I

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MANA PRN 28 ASIA 1995 6 10

-2000 -1000 0 1000 2000

CROSS-CORRELATION between LC OBS and LC EST

............ ............... .................

.. ............... ... . ........... ...... . .. .. ..

-2000 -1000time delay :Tau (sec)

I I

1000 2000

Fig. A.5.10.c) MANA - PRN 28 (10 6 1995) - [segment 2.b]Auto Correlation of LCOBS (Roo) and LCEST (R).Cross Correlation between them (Roe)

Unit: [cycles] 2

186

Oo.-

0o2Or<r

I.--

-oLUo

0o!

-3000

. 0

0o

2 -0.5

3000

_1-3000-3000 3000

segment 2bfnV) I -

................ .... ......

L-

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"RESIDUAL" = difference LC Observed - LC Estimated

5.5 5.55 5.6 5.65 5.7 5.75 5.8 5.85 5.9 5.95Time (sec)

MANA PRN 28 : o= LC OBSERVED

6x 10'

*= LC ESTIMATED

5.5 5.55 5.6 5.65 5.7 5.75 5.8 5.85 5.9 5.95Time (sec)

Fig. A.5.11.a) : MANA - PRN 28 (10 6 1995) - [segment 2.c]Phase residual LC.DIFF, determined as the differencebetween LC.OBS and LC..EST.Unit: [cycles]

188

6

x 104

: segment 2.c)

o80 30110 O

Sd

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MANA PRN 28 ASIA 1995 6 10

0o

I00

-4000 -3000 -2000 -1000 0 1000 2000 3000 4000

CROSS-CORRELATION between LC OBS and LC EST

-4000 -3000 -2000 -1000 0 1000 2000 3000 4000time delay :Tau (sec)

Fig. A.5.11.c) MANA - PRN 28 (10 6 1995) - [segment 2.c]Auto Correlation of LC.OBS (Ro) and LCEST (Re).

Cross Correlation between them (R,)

Unit: [cycles] 2

190

segment 2c

-4000 -3000 -2000 -1000 0 1000 2000 3000 4000

. . . ...

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6 6.05 6.1 6.15 6.2 6.25Time (sec) x 10'

MANA PRN 28 : o = LC OBSERVED *= LC ESTIMATED

6 6.05 6.1 6.15 6.2 6.25Time (sec) x 104

Fig. A.5.12.a) MANA - PRN 28 (10 6 1995) - [segment 2.d]

Phase residual LC.DIFF, determined as the difference

between LCOBS and LCEST.

Unit: [cycles]

192

: segment 2.d)

.............

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.....

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MANA PRN 28 ASIA 1995 6 10 segment 2d

1000 2000

-200000

-1000 1000 2000

3000

3000

CROSS-CORRELATION between LC OBS and LC EST

-1000 1000 2000 3000time delay :Tau (sec)

-1000

Fig. A.5.12.c) MANA - PRN 28 (10 6 1995) - [segment 2.d]Auto Correlation of LCOBS (Ro) and LCQEST (Rd).Cross Correlation between them (Roe)

Unit: [cycles] 2

194

U,ml0O

0

I- -10-30wCO

00

304

I I .. I .. . . . . . . . . .. . . .... ! i ....

g I I i !

00 -2000

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0.5

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1000 2000

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GPS DATA: receiver: LIGO

station: 0028 satellite: PRN 09

7.5 7.55Time (sec)

90 9012 -60

0021 :. .... 5.* 30

240 300270

18 ********;*******, ,*******I*******24~0 300

270 acquisition date: 25 9 1996

station: 0028 satellite: PRN 094t6

o 44

42

40

38

7.6x l 4

7.45 7.5Time (sec)

7.55

Satellite visibility chart for PRN 09 (skymap).Elevation and azimuth of PRN 09 with respectto the station 0028

196

I

z 18

> 16W

IA

7.45

Fig. A.6.1 :

7.6

x IU

I

.......... ........ ...................................- ....... .................... - - - - - -. ... ... ... ... . . . .. . .

.* -...... ... .... ........ ...........

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mA

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LIGO 0028 PRN 09 25 9 1996

7.5 .527.5

7.5 7.52 7.54Time (sec)

Signal to Noise Ratio for L1 and L2

7.52 7.54

Time (sec)

Station: 0028- Satellite: PRN 09Data acquisition date 25 9 1996Signal-to-Noise-Ratio (SNR) for LI and L2.

197

46 7.48

(,

618IC= 16

S147.

14

12

10

87.4

7.56 7.58x 10'

16 7.48 7.56 7.58

Fig. A.6.2 :

x 10

58

= = i I I

........ ....... ....... .... ... ........ .... ..

............................... ............................................... .. .........

.............................. ..............··. ·· ·· ·· ·· ·· r · ·· · · · ·I· · · ·.... : ................ . .... .... .............·V4 ~·/·· · · ·· ·· r · ·· ·· ·· ··

I

90 9012 * 60

15 '. ... 4..5.- 1 30

18 .. ...e ... . *: , .... ... .18 ********:******* 0)************** 0O

21* **** *30

240 * 300270

GPS DATA: receiver: LIGO acquisition date: 25 9 1996

station: 0036 satellite: PRN 09 station: 0036 satellite: PRN 09

7.4 7.45 7.5Time (sec)

50

45

40

7.357.55 7.6

x1047.4 7.45 7.5 7.55 7.6

Time (sec) x104

Satellite visibility chart for PRN 09 (skymap).Elevation and azimuth of PRN 09with respect tothe station 0036

198

0)

1 20z0 18

116w

A

7.35

.. ...... ................... ..

............ .. -................. ...............

Fig. A.6.3 :

ml n I I I

I.-

·--

53~

LIGO 0036 PRN 09 25 9 1996I I I I I I I i I

7.4 7.42 7.44 7.46.7.487.5.7

7.4 7.42 7.44 7.46 7.48 7.5 7.52 7.54 7.56Time (sec)

Signal to Noise Ratio for L1 and L2

7.4 7.42 7.44 7.46 7.48 7.5 7.52 7.54 7.56

................... . . .

S........... ...............

IL I i I I I I I1 I

7.4 7.42 7.44 7.46 7.48Time (sec)

7.5 7.52 7.54

Fig. A.6.4 : Station: 0036- Satellite: PRN 09Data acquisition date 25 9 1996Signal-to-Noise-Ratio (SNR) for LI and L2.

199

o22

o 20

C

> 16W 14

I I I I .

I I I I !

x 104

x 104

7.56

x 104

oo

GPS "OBSERVED" Phase Residuals for: LIGO PRN 09 - ASIA 1996 9 25

5 I7.47 7.48 7.49 7.5 7.51 7.52 7.53 7.54 7.55 7.56 7.57

GPS "ESTIMATED" Phase Residuals computed from the analysis of SNR variation x 105 A.•

7.48 7.49 7.5 7.51 7.52 7.53 7.54 7.55 7.56 7.57.I i i ii i i ii i J

7.47 7.48 7.49 7.5 7.51 7.52 7.53 7.54 7.55 7.56 7.57Time (sec) x 10

Fig. A.6.5: Stations: 0028- 0036 Satellite: PRN 09 -Data acquisition date 25 9 1996The observed phase residual (LC.OBS) is compared with themultipath phase error estimated from the SNR (LCJEST)(differential mode)Unit: [cycles]

200

I I i | I jI I

I~.~ I :· I..

-0.

0.

_n

0.

?SHI! I

% A % ...... . ." " " ".'°.-.7 .... ..

-..•-..:•'•

7.47

0036 - 0028 PRN 09 - LIGO 1995 9 25

7.47 7.48 7.49 7.5 7.51 7.52 7.53 7.54 7.55 7.56 7.57Time (sec) x 104

o /5 I I I IA.": .".. ..... ... . . ".. ......;' ....

%II :. :•I. i i I

7.47 7.48 7.49 7.5 7.51 7.52 7.53 7.54 7.55 7.56 7.57Time (sec)

0028- 0036 Satellite: PRN 09Data acquisition date 25 9 1996LC.OBS and LC.EST compared for t=7.47 -7.58 10 4 secUnit: [cycles).

201

0

5-0

0.

-0.

Fig. A.6.6 :

x 104

-0._v

"RESIDUAL" = difference LC Observed - LC Estimated

7.48 7.49 7.5 7.51 7.52 7.53 7.54 7.55 7.56 7.57Time (sec) x 10

o - LC OBSERVED * = LC ESTIMATED

7.48 7.49 7.5 7.51 7.52 7.53 7.54 7.55 7.56 7.57Time (sec) x 10

Fig. A.6.7.a) 0028- 0036- PRN 09 (25 9 1996)Phase residual LC.DIFF, determined as the differencebetween LCOBS and LC.EST.Unit: (cycles]

202

- .•

7.47I I I I I

7.47

I · · · L · _ _ _ · ·05 EL

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LC D

IFF

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CROSS-CORRELATION between LC OBS and LC EST

-- 9

-8000 -6000 -4000 -2000 0 2000 4000 6000time delay : Tau (sec)

Fig. A.6.7.c) 0028- 0036- PRN 09 (25 9 1996)Auto Correlation of LCOBS (Ro) and LC.EST a(R).Cross Correlation between them (Ro)Unit: [cycles]2

204

o)0

-J0

u)ILl0wo-.JoooI-0

3

I-

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8000

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21 . 30

240 ' 300270

GPS DATA: site: LIGO acquisition date: 26 9 1996

receiver : 0028 satellite: PRN 15 receiver: 0028 satellite: PRN 15

CD"O

I 310

I-3052 305

300A

Time (sec) x 1047.4 7.5 7.6 7.7 7.8 7.9

Time (sec) xlO1

Satellite visibility chart for PRN 15 (skymap).Elevation and azimuth of PRN 15 with respect tothe station 0028

206

Fig. A.7.1 :

wAhi •

LIGO 0028 PRN 15 26 91996

.. ... .... ... .... ..... ...... .. ... ...... ....

7.5 7.55 7.6 7.65 7.7 7.75 7.8 7.85x 10I

Signal to Noise Ratio for L1 and L2

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Signal to Noise Ratio for L1 and L2

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Station: 0036- Satellite: PRN 15Data acquisition date 25 9 1996Signal-to-Noise-Ratio (SNR) for LI and L2.

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CROSS-CORRELATION between LC OBS and LC EST x 104

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Fig. A.7.10.c) : 0028- 0036- PRN 15 (25 9 1996) [segment #4]Auto Correlation of LCOBS (Roo) and LC._EST (Ree).Cross Correlation between them (Roe)

Unit: [cycles] 2

226

..

0

o

Io1_

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240 300270

GPSDATA: site: LIGO acquisition date: 26 9 1996

satellite: PRN 25170

165

160

7.5 7.6 7.7 7.8 7.9Time (sec)

7.

receiver: 0028 satellite: PRN 25

5

x 10'

7.6 7.7 7.8 7.9Time (sec) x 10'

Satellite visibility chart for PRN 25 (skymap).Elevation and azimuth of PRN 25 with respect tothe station 0028

228

receiver: 0028

Fig. A.8.1 :

.. .. .... ......... % ................ ...... ..... .

..

.°°

-1 gzr%

LIGO 0028 PRN 55 26 9 1996

7.65 7.7 7.75

Signal to Noise Ratio for L1 and L2

7.65

7.65

7.7

7.7Time (sec)

7.75

7.75

Fig. A.8.2 : Station: 0028- Satellite: PRN 25Data acquisition date 26 9 1996Signal-to-Noise-Ratio (SNR) for LI and Lz.

229

7.6

. . I I .

35

-. 30I

. 25

g 20

7.

25

20

15

10

7.

25

20

15

10

7.5

7.85x 10

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7.6 7.8 7.85x 104

55

55

5

5

5

II I II A A A................ ................ .......... ..... ................... ...................... ... ... ... ... ... ... ... ... ... ... ...

GPS DATA: site: LIGO

receiver: 0036 satellite:PRN 25

Time (sec) x 104

90 9012 - 60

15 45....... 30

18 ....... ; *.... ..*0*...... .......* 0

21 30

240 300270acquisition date: 26 9 1996

receiver: 0036 satellite: PRN 25

Time (sec) x 104

Satellite visibility chart for PRN 25(skymap).Elevation and azimuth of PRN 25 with respect tothe station 0036

230

Fig. A.8.3 :

9

LIGO 0036 PRN 25 26 9 1996

7.65 7.7 7.75

Signal to Noise Ratio for L1 and L2

7.65

7.65

7.7

7.7Time (sec)

7.75

7.75

Fig. A.8.4 : Station: 0036- Satellite-. PRN 25Data acquisition date 26 9 1996Signal-to-Noise-Ratio (SNR) for LI and Lz.

231

35CM` 30I

. 25

& 20LU

ýj7.a

25j

7.85x 10'

zu15

10

7.5

25

20

15

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7.6

7.6

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7.85

7.85x 10'

1_ • • . . .I

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. . ... .. .. .. .. . .. .... . .. ... . .. ... ... ..... .....

55

5

5

.... ... ... .................. ..... ..... .... ...

.... ... ... ... .... ... ... ... ... .... ... .. ... ... .... ... ... ... ...

GPS "OBSERVED" Phase Residuals for: LIGO PRN 25 - ASIA 1996 9 25

55 7.6 7.65 7.7 7.75 7.8GPS "ESTIMATED" Phase Residuals computed from the analysis of SNR variation x 104

0.2

0.1

0

-0.1

-0.2

7.

0.2

0.1

0

-0.1

-0.2

7.

7.6 7.65 7.7Time (sec)

7.75 7.8

xlo4

Fig. A.8.5: Stations: 0028- 0036 Satellite: PRN 25-Data acquisition date 26 9 1996The observed phase residual (LC.OBS) is compared with themultipath phase error estimated from the SNR (LC..EST)(differential mode)Unit: [cycles]

232

I I I I I

S...... .................. ........ . ............. ...........................

. ... ... ... ... ...... ..... ..... • . '..... o........... ................ . o...... .... .... ..... -.......I I I I I

55 7.6 7.65 7.7 7.75 7.8Comparison LC OBSERVED vs LC ESTIMATED x104

0.2

0.1

0

-0.1

-0.2

7.5

_ I - II. ... ... ... ... ... ... ... ....· :·· · · · · · ·................. ·; .. .. .. .. .. . . . .. .. .. .. . . .. .. .

II I I I

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I I I I I

5

0036 - 0028 PRN 25 - LIGO 1995 9 25

7.6 7.65 7.7 7.75 7.8Time (sec)

7.6 7.65 7.7 7.75 7.8Time (sec) x 104

0028- 0036 Satellite: PRN 25Data acquisition date 26 9 1996LCOBS and LC..EST compared for t=7.56 - 7.9 10 4 secUnit: icycles]

233

I I I I I 10.2

-0.1

-0.2

7.55

0.2

uI,,I

cc

Cn 00o -0.1

-0.2-0.2

x 10

7.55

Fig. A.8.6 :

1

0036 - 0028 PRN 25 - LIGO 1995 9 25

7.6 7.62

7.62

Time (sec)

Time (sec)

7.64

7.64

7.66

7.66

0028- 0036 Satellite: PRN 25Data acquisition date 26 9 1996LC_OBS and LC_EST compared for t=7.56 - 7.7 10 4 secUnit: [cycles]

234

-0.1

-0.2

[ I I I I I ~

I I I 1 II

7.687.56

-0.1

-0.2

7.56

7.58

7.58

x 10

... . . . . i

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." ." "........ . ........ . .. .. " .... .. "....... .... ..... .. .. .: . . . . . . . . . . . ... .: . ... . • ...... i ......... -...• -...r ... .. .....; .... ... .. ...'1:: I r. I I I . . •I - i .I - - - -- - - " I• -'.. . . .'-. . .. . . . !. . . . . . .. . . . . . .. i i . . .•- -.. .

Fig. A.8.7 :

7.68

x 10

::i

"RESIDUAL" = difference LC Observed - LC Estimated LIGO PRN 25 segm #1

7.56 7.58 7.6 7.62 7.64 7.66Time (sec)

o = LC OBSERVED * = LC ESTIMATED

7.58 7.6 7.62 7.64 7.66Time (sec)

7.68x 10

Fig. A.8.8.a) : 0028- 0036- PRN 25 (26 9 1996) [segment #1]Phase residual LC.DIFF, determined as the differencebetween LCOBS and LC..EST.Unit: [cycles).

235

0.2

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o')

0

o -0.2

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7.68x 10

7.56

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LIGO PRN 15 26 9 96

-60UU -4UU0 -zUUU U zUUU 4UUU 6UUU 8000

CROSS-CORRELATION between LC OBS and LC EST

-4000 -2000time delay :Tau (sec)

2000 4000 6000 8000

Fig. A.8.8.c) : 0028- 0036- PRN 25 (26 9 1996) [segment #1]Auto Correlation of LC.OBS (Roo) and LC.EST (t,).Cross Correlation be.tween them (R

Unit: [cycles] 2

237

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1

0.5

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7.7 7.72 7.74 7.76 7.78 7.8Time (sec)

o - LC OBSERVED *= LC ESTIMATED

7.7 7.72 7.74 7.76 7.78 7.8Time (sec)

Fig. A.8.9.a) : 0028- 0036- PRN 25 (26 9 1996) [segment #2]Phase residual LC..DIFF, determined as the differencebetween LC.OBS and LC.EST.Unit: [cycles]

239

7.82x 104

7.82x 104

LIGO PRN 25 segm #2

LC D

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LIGO PRN 25 269 96 segment 2

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CROSS-CORRELATION between LC OBS and LC EST

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Fig. A.8.9.c) : 0028- 0036- PRN 25 (26 9 1996) [segment #2]Auto Correlation of LC..OBS (Roo) and LC.EST (R).Cross Correlation between them (Ro)Unit: [cycles] 2

241

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.........""'......."...... ............-.............................. ............... - .............. ...... .- ......... .... .............-... ." ".....'. \

S -....................

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7.48 7.5 7.52 7.54 7.56GPS "ESTIMATED" L1 computed from the analysis of SNR variation

7.48

7.48

7.5 7.52 7.54Comparison L1 OBSERVED vs L1 ESTIMATED

7.5 7.52Time (sec)

7.54

7.56

7.56

Fig. A.9.1 : 0028- 0036 Satellite: PRN 09Data acquisition date 25 9 1996

LLOBS and LilEST compared for t=7.46 -7.58 104 secUnit: [cycles]

243

0.10.05

0-0.05-0.1

7.46

0.10.05

0

-0.05-0.1

S................ . ...... ......... .

I I I I I

7. 46

0.1w 0.05WI 0

0 -0.05" -0.1

7.58x 10'

7.58

x 104

7.58

x 10'

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7.46

. . . .. . .

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0.15

0.1

0.05

0

-0.05

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-0.27.4

0.15 -

0.1--

w

wa -0.05

-0.15 -

-0.27.46

LIGO 1995 9 25 PRN 09 - Single Difference 0028 0036

7.48

7.48

7.52Time (sec)

7.5 7.52Time (sec)

7.54

7.54

7.56

7.56

Fig. A.9.2 : 0028- 0036 Satellite: PRN 09

Data acquisition date 25 9 1996L..OBS and LiEST compared for t=7.47 - 7.58 10 4 secUnit: [cycles]

244

I I I I

7.x 10

I I I I I

.............. ............. ...... .. . ........

.............................. ..... .... ..... .... ,.......... .... ...... • ." ;t ....... •./ .............................. . .......... .. ... ..... ................

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581

587.

x10

· · · ·

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46

c i. ·

!.. . . . .. . . . . .

"RESIDUAL" = difference L1 Observed - L1 Estimated LIGO PRN 09

I. I I1

7. 7.5 7.54 j7.5 7.52 7.54

Time (sec)

o = L1 OBSERVED * = L1 ESTIMATED

7.56

,I. 1

7.48 7.5 7.52 7.54 7.56Time (sec)

Fig. A.9.3.a) : 0028- 0036- PRN 09 (25 9 1996)Phase residual LL.DIFF, determined as the differencebetween LiOBS and LLEST.Unit: [cycles]

245

0.15

0.1

0.05

0

-0.05

-0.1

7.46 7.48

0.1

0

0.0

-0.C

-0

7.58x104

.1 .....

5 ......

0 .

5 ......

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I. I I i I7.46 587.10

x 10"

1

i

,,

LIGO PRN 09: Single Difference

9 ..... .

S...... ..... ...... .. . ..

......... .. .. . ....

7.46 7.48 7.5 7.52 7.54 7.56

4

-J0

0,I._aCl

,.

7.58x 104

7.46 7.48 7.5 7.52 7.54 7.56 7.58

x 104

0.050

-0.05-0.1

7.46 7.48 7.5 7.52 7.54 7.56 7.58Time (sec]

n

Power Spectra Density

10- 10-2

10" 10" 10-2x 10

Fig. A.9.3.b) : 0028- 0036- PRN 09 (25 9 1996)PSD of LLOBS, LL.EST and LIDIFF.Unit: [cycles] 2

246

0.10.05

0

-0.05-0.1

.i

I..:::

0.10.05Co

w O" -0.05

-0.1

X- r

fAf.. ......- ...... -. .....: .. .... * .. . . . . ..... 1

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10

10'

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.... ... ...... .....

.. ......

I10l

LIGO PRN 09 26 9 96 :Single Difference

-2000 2000 4000

CROSS-CORRELATION between L1 OBS and L1 EST

-2000time delay: Tau (sec)

2000 4000

Fig. A.9.3.c) 0028- 0036- PRN 09 (25 9 1996)Auto Correlation of LCOBS (Roo) and LCEST (Ree).Cross Correlation between them (Roe)Unit: [cycles] 2

247

0

wcIn-

-J

0C.,J0ro<•

-4000 -2000 0 2000 40006000

-6000 -4000

t=.

OIeA

6000

e -0.5

4

. . . . . . . . . . . . . . . . . . ...... ... . . ... . ... .. . . .

-I

-6()00 -4000 6000I

mA =41

-,, 3- 6000

Auto-Spectral Power Density3000

2500

150C

81000500C

7.46 7.48 7.5 7.52 7.54 7.56 7.58Time (sec) x 10'

COHERENCE OF L1 OBS and Li EST

10e 10-Z

frequency [Hz]10

- 1

300C

. 250C

-) 200C0

150C

100(Ca.

C50

10 10-2

frequency [Hz]

CROSS-SPECTRAL Power Density

.... :... . . ... ..

10- 10-2 10- 1

frequency [Hz]

Fig. A.9.3.d) : 0028- 0036- PRN 09 (25 9 1996)Auto Spectral Power Density of LC_OBS (Soo) and ofLC_EST (See). Cross PSD between them (Soe)Unit: [cycles] 2

Coherence function of LC_OBS and LC..EST

248

0.15

0.1

0.05

0

-0.05

-0.1

I i -

i. f. *1.IF. ~.

: -:--.::::: -: - .::::::: : : : ::::::: :. ::::: : :: : : : : : : :

1 i ~iiriiii i" ii ii i i iil1.~ .~... . .\..--

L -· .- .j

10-1

0.8

0.6

0.4

0.2

0

10-4

I

--

10l

. " .. . ' . . ... ..

• " ' .. . . . .. ... .... . . . .

. .. • .. . . . . ...

'

"''

L.

10-

LIGO PRN 095:L1

GPS "OBSERVED" L2 : LIGO PRN 09 - Single Difference 0028 0036

7.48 7.5 7.52 7.54 7.56GPS "ESTIMATED" 12 computed from the analysis of SNR variation

0.

-0.

-0.:

0.

0.

-0.

--0.

7.56

7.5 7.52 7.54 7.56Time (sec)

Fig. A.9.4: 0028- 0036 Satellite: PRN 09- Data acquisition date 25 9 1996Lz_.OBS and Lz.EST compared for t=7.467-7.58 10 4 secUnit: [cycles]

249

0.:

7.5 7.52 7.54Comparison L2 OBSERVED vs L2 ESTIMATED

.. .... ... ..... ....... ...... .1 .\. . :.. . . . .. . . .... . ...... ,: ....... . .. . .. ... ... ;.

S'• ; : ii : I

I I I I

2

1

0

1

27.

2'7.

7.xiO

2

1

0-

1

46

46

58t

.584

7.48

7.48

0.2

0.1

0

-0.1

-0.27.

7.

x 10

I . . ~ Il I

7.

x 104

·

· · · · · 1

i

46

58

LIGO 1995 9 25 PRN 09 - Single Difference 0028 0036

7.5 7.52Time (sec)

7.54 7.56

Time (sec) x 10

Fig. A.9.5: 0028- 0036 Satellite: PRN 09Data acquisition date 25 9 1996Lz.OBS and LEST compared for t=7.47 - 7.58 10 4 secUnit: [cycles]

250

0.2

-0.1

0_

...................... .. ............. ...... .. ......... .. ................... .............

I I I

7.46 7.48 7.58

x 10'

"RESIDUAL" = difference L2 Observed - L2 Estimated LIGO PRN 09

7.48 7.5 7.52 7.54 7.56Time (sec)

o = L2 OBSERVED * = L2 ESTIMATED

7.48 7.5 7.52 7.54 7.56Time (sec)

7.58x 10

Fig. A.9.6.a) 0028- 0036- PRN 09 (25 9 1996)Phase residual L2zDIFF, determined as the differencebetween Lz.OBS and LzEST.Unit: [cycles]

251

0.15

0.1

0.05

-0.05

-0.1

-0.15

_n-'..

7.'I I

7.58x 10'

0.2

0.1

-0.1

-n o7.46

S ............. .............

F . .

B .

46

- .. .

I-

i_ .....-

LIGO PRN 09: Single Difference

cn 6mO

o0

n 2a.

7.48 7.5 7.52 7.54 7.56 7.58x 10'

7.48

10 4

6

0co2CL.

r7.5 7.52 7.54 7.56 7.58

x 10'

7.48 7.5 7.52 7.54Time [sec]

Fig. A.9.6.b)

7.5(

u- 6u-94o

02

6 7.58

x 10'

10-4

Power Spectra Density

: :...: . ........ . ......: o o -. .. ... • o. .

· · · · · · · · : i ii i i'ii'iiiil

~..:::J :.• • ... °° ° • . °... . o • .oo,': : :::::::l=

10

10l

10-4

10-2 10-'

10-210 10

10-2

0028- 0036- PRN 09 (25 9 1996)PSD of LC.OBS, LC..EST and LCDIFF.Unit: [cycles] 2

252

0.1

-0.1

_A' #

i

...... ..4.. . ....

... ... .. . .. I. . i " s,i j: I··l jt '' IJ '''V

,- +A-VV- V - \ -- -- - --

7.46

-0.1

0n

7.46

0.1

0

-0.1

-n o

"· " " ' " ; ;1 " . ..' " " " ' '

: ; ::'• i::; : : : ::

7.46

/ : :::::: : : ::::: : : ::: *1

10-'

I

I i I I l i

@ I i I I n

·· ·

'

*

0.2

'

LIGO PRN 09 26 9 96 :Single Difference

O

o0

-t

't

0

-4000 -2000time delay : Tau (sec)

2000 4000

6000

6000

Fig. A.9.6.c) : 0028- 0036- PRN 09 (25 9 1996)Auto Correlation of LC..OBS (Roo) and LC.EST (Re).Cross Correlation between them (Roe)Unit: [cycles] 2

253

-6000 -4000 -2000 0 2000 4000

CROSS-CORRELATION between L2 OBS and L2 EST

6000-6000 -4000 -2000 0 2000 4000

oI0U

0.5

-0.5

-1

i I I I I I

I I I I -- I I

-6000

Ii i i i i i

-

LIGO PRN 095 :L2

7.48 7.5 7.52 7.54 7.56 7.58Time (sec) x 10'

COHERENCE of L20 Bs and L2EST

frequency [Hz]

CROSS-SPECTRAL Power Density

0.8

0.6

0.4

0.2

Atio-4 102-

frequency [Hz]10- 1 10. 1-0 10- 2

frequency [Hz]

Fig. A.9.6.d) : 0028- 0036- PRN 09 (25 9 1996)Auto Spectral Power Density of LC_OBS (Soo) and ofLC..EST (Se). Cross PSD between them (Soe)

Unit: [cycles] 2

Coherence function of LC.OBS and LCEST

254

.,,...tI-I.

0.2

0.1

0

-0.1

0A

7.46

10-I

Auto-Spectral Power Density

·

0%k r.f P£•f%

···· · · · ·· ·· ···· · · · ·· · ·· ····· · · · ·· ·· ····· · · · · ·· ·· ····· · · · · · ······ · · · ·· · ···: · ··' ̀ ·'·` =-·~i '·':''·' =`·';·'·::···· · · · ·· ·· ······ · · · ·· ·· ···· · · · ·· · ·· ··· · · · · ·· ·· ··· · · · · · · ·~·.·..·······.·2\ · · · 1····t··. ·. · · · ~~·

· · · · · · · · · · · ·· · · · · · · · · · · ·

· · · · · · · · · · · · ·"" · · · · · · · · ·· · · · · · · · · · · · ·

· · · · · · · · · · · ·· · · -··' ""' · · '·'···-···~L··~

· · · · · · · · · ·· · ·· · · · · · · · · · · · ·· · · · · · · · · · · · ·

· · · · · · · · · · · ·"" · · · · · · ·

"· ...."· ' ' """'

"'· ''"

'V'' UY"

'

·'

·'

10 410-2-10

90 90

270GPS DATA: receiver location: SOUTHERN CALIFORNIA acquisition date: 23 1 1997

station: COSE (trimble) satellite: PRN 01

Time (sec)

200

• 150

100

6x 104

station: COSE (trimble) satellite: PRN 01

Time (sec) x 104

Satellite visibility chart for PRN 01 (skymap).Elevation and azimuth of PRN 01with respect tothe station COSE

255

100

Fig. A.9.1 :

)

* !............ ............. .............. ......... ..... .....--- ........ ..... .

0

COSE (trimble) PRNOI 2311997

5.54.5Time (sec) x 104

Signal to Noise Ratio for L1 and L2

I I IIIII II I. . .. . .. . . . . .. . .. . . .. . .. . .. . .. . . . . . .. . . .. . .. . . . . . . .. ... . . . . .. . .. .. . . . . . . .. . . . . . . . . . . . . . . . . . .·· · l · `---~'

3.6 3.8 4 4.2 4.4 4.6 4.8 5 5.2 5.4 5.6

I - - I--- : -- I - -- I -:I:I S I I

3 .6.8.. .. .. . . ........ . ... .

3.6 3.8 4 4.2 4.4 4.6 4.8 5 5.2 5.4 5.6Time (sec) x 10

Station: COSE - Satellite: PRN 01Data acquisition date 23 1 1997Signal-to-Noise-Ratio (SNR) for Li and Lz.

256

I I I I

I I

3.5

100

50

320

~10

0

20

Fig. A.9.2 :

· 1 ·

i I

_r

COSE (trimble) PRN 01 23 1 1997I |

I

. ..............-

I-

GPS "OBSERVED" Phase Residuals for: COSE (tr) PRN 01 - CALIFORNIA 23 11997

3.6 3.8 4 4.2 4.4 4.6 4.8 5 5.2 5.4 5.6GPS "ESTIMATED" Phase Residuals computed from the analysis of SNR variation x 10

3.6 3.8 4 4.2 4.4 4.6 4.8 5 5.2 5.4 5.6Comparison LC OBSERVED vs LC ESTIMATED x 10

3.6 3.8 4 4.2 4.4 4.6Time (sec)

4.8 5 5.2 5.4 5.6

x 10

Station: COSE - Satellite: PRN 01- Data acquisition date 23 1 1997The observed phase residual (LC.OBS) is compared with themultipath phase error estimated from the SNR (LC..EST)Unit: [cycles]

257

-.... .... ... ......... . ......................... ......... ........ ... ............... ... . . .... ; .

...... .... ............ .................... ..... ....... .... .................... ......... .. -, • . '

0.2

0

-0.2

-0.4

-0.6

-0.8

0.2

0

-0.2

-0.4

-0.6

-0.8

0.2

-0.2

O-0.4

- -0.6-0.8

,... ........... ,I......r.....l..... ........ J........ !..

.-.~... ... t....................--:

.. .. .. .. .. .. .. .. .. .. ..* .. .... ........ ........ ..: ~

- ··! · · · ........ ....~·· ·· ·! · ·· · ·!· ·· · ·a · ·· · l· · ·

. .. .. ... .. .. ... .. .. ... . ... .. . ... .. .. ... . ... .. . ... .. ...

Fig. A.9.3 :

COSE (trimble) PRN 01 - SOUTHERN CALIFORNIA 23 1 1997

3.6 3.8 4 4.2 4.4 4.6 4.8 5 5.2 5.4 5.6Time (sec) x 10'

3.6 3.8 4 4.2 4.4 4.6 4.8 5 5.2 5.4 5.6Time (sec) x 10'

Station: COSE - Satellite: PRN 01Data acquisition date 23 1 1997LCOBS and LC_.EST compared for t=3.5 - 5.7 10 4 secUnit: [cycles)

258

0.2

a

-0.2

-0.4

-0.6

-0.8

0.2

0

-0.2

-0.4

-0.6

I i I I I I i I I I. . ........ ......•o ., ,. ,, • .. . o, , o o , , ................ o-,- .....•o .. o ......... o'o

" '

... . . . ... ....... •......... ........ ............. . ._..... .. ... ..•· · · ·· · · .·· · · ·· ·

~~~·~····:· :''''~'''' i~''`' :' t''' · ·''~'·''

.. .. . ,.. .. .. ., .. . .. . ,. . ... • .. . . .,,. . . .•. . . ., . ,. . . . , . ° . .. . .

Fig. A.9.4 :

3.6 3.8 4 4.2y.o

"RESIDUAL" = difference LC Observed - LC Estimated

3.5 3.55 3.6 3.65 3.7 3.75 3.8 3.85 3.9 3.95 4Time (sec) x 10'

o - LC OBSERVED (COSE 01 trimble Part la) * LC ESTIMATED (COSE 01 trimble Part 1 a)

3.5 3.55 3.6 3.65 3.7 3.75 3.8 3.85 3.9 3.95 4Time (sec) x 10

Fig. A.9.5.a) : COSE - PRN 01 ( 23 1 1997) - [segment la]Phase residual LCJDIFF, determined as the differencebetween LC.OBS and LCEST.Unit: [cycles]

259

: Part la

...

..

%.t..........

..

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ii

i'

•%

....... ..

...... ...... ..

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···

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Ile:

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00 (D

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:........J............::::{::ii:::•"

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. ....~. .•.

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cc

co

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31o

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.........:...............I

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,

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.,.,

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·~···~·-····-·-

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4r·····s·5· ·

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COSE (trimble) 23 1 1997

-2000 2000 4000

CROSS-CORRELATION between LC OBS and LC EST..... I

time delay :Tau (sec)

Fig. A.9.5.c) COSE - PRN 01 ( 23 1 1997) - [segment la]Auto Correlation of LCOBS (Roo) and LC_EST a(t).Cross Correlation between them (Ro)Unit: [cycles] 2

261

F·v

C,

0

oo

-1

-60

w

0O0I

-60

604-4000 -2000 0 2000 400000

00 -4000

00

00

0

2o

o0I

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00

60

0.5

0

-0.5

_.

-6000

.............. .......... o.......................

.. . . . . ... • . . . . . . . . . . . . . . . . . .

-4000 -2000 2000 4000 6000

segment la

S..

.. . .. . . .. .. .. . .. .. . .. . . .. . . . . .. .....

. .. .. .. .. .. .. ..

Cohe

renc

eO

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LC O

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/ LC

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RC

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f)(

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) and

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o

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0

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"RESIDUAL" - difference LC Observed - LC Estimated

4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5Time (sec) x 10

o - LC OBSERVED (COSE 01 trimble Part Ib) * LC ESTIMATED (COSE 01 trimble Part Ib)

4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5Time (sec) x 10

Fig. A.9.6.a) COSE - PRN 01 (23 1 1997) - [segment Ib]Phase residual LC.DIFF, determined as the differencebetween LC.OBS and LC.EST.Unit: [cycles]

263

0.1

0.05

-0.05

04

4

: Part lbA =

I o io

o CO

oo

10

Ct,)

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PSD

of L

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COSE (trimble) 23 1 1997 segment lb1

0

-1-1

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1

CROSS-CORRELATION between LC OBS and LC EST x 10

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1time delay :Tau (sec) x104

Fig. A.9.6.c) : COSE - PRN 01 (23 1 1997) - [segment lb]Auto Correlation of LC.OBS (Roo) and LCEST at,.Cross Correlation between them (RUnit: [cycles] 2

265

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5 5.1 5.2 5.3 5.4 5.5 5.6 5.7Time (sec) v An

o - LC OBSERVED (COSE 01 trimble Part Ic)

A IU

* - LC ESTIMATED (COSE 01 trimble Part 1 c)

5 5.1 5.2 5.3 5.4 5.5 5.6 5.7Time (sec) x 10'

Fig. A.9.7.a) COSE - PRN 01 ( 23 1 1997) - [segment 1c]Phase residual LC..DIFF, determined as the differencebetween LC..OBS and LC.EST.Unit: [cycles}

267

: Part lc)

L" .

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COSE (trimble) 23 1 1997 segment 1c0e -

-6000 -4000 -2000 0 2000 4000 6000

-6000 -4000 -2000 0 2000 4000

CROSS-CORRELATION between LC OBS and LC EST

4-I

-8000 -6000

Fig. A.9.7.c)

-4000 -2000 0 2000 4000 6000time delay :Tau (sec)

COSE - PRN 01 ( 23 1 1997) - [segment Ic]Auto Correlation of LCOBS (Roo) and LC_.EST (Ree).Cross Correlation between them (Roe)Unit: [cycles] 2

269

0co0O

o

0

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8000

8000-8000

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Fig. A.12.2 : Station: GS29 - Satellite: PRN 01Data acquisition date 24 1 1997Signal-to-Noise-Ratio (SNR) for LI and L2.

299

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GPS "OBSERVED" Phase Residuals for: GS29 (ash) PRN 01 - CALIFORNIA 24 1 1997I I I I I

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Fig. A.12.3 : Station: GS29 - Satellite: PRN 01Data acquisition date 24 1 1997The observed phase residual (LCOBS) is compared with themultipath phase error estimated from the SNR (LC_ES'I)Unit: [cycles]

300

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Fig. A.12.4 : Station: GS29 - Satellite: PRN 01Data acquisition date 24 1 1997LC.OBS and LC.EST compared for t=3.5 - 5.7 10 4 secUnit: (cycles]

301

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o - LC OBSERVED (GS29 01 Ash Part la) * = LC ESTIMATED (GS29 01 Ash Part la)

3.4 3.5 3.6 3.7 3.8 3.9 4Time (sec) x 104

Fig. A.12.5.a) : GS29 - PRN 01 ( 24 1 1997) - [segment la]Phase residual LC..DIFF, determined as the differencebetween LC.OBS and LC..EST.Unit: [cycles]

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CROSS-CORRELATION between LC OBS and LC ESTI I I I I I I I

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Fig. A.12.5.c) GS29 - PRN 01 (24 1 1997) - [segment la]Auto Correlation of LC..OBS (Roo) and LCEST (R).

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CROSS-CORRELATION between LC OBS and LC EST

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Fig. A.12.6.c)

0 2000 4000 6000 8000time delay :Tau (sec)

GS29 - PRN 01 (24 1 1997) - [segment Ib]Auto Correlation of LCOBS (Roo) and LC..EST cR).Cross Correlation between them (Ro)

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o = LC OBSERVED (GS29 01 Ash Part Ic) * = LC ESTIMATED (GS29 01 Ash Part Ic)

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Fig. A.12.7.a) : GS29 - PRN 01 (24 1 1997) - [segment ic]Phase residual LC.DIFF, determined as the differencebetween LCOBS and LCEST.Unit: [cycles]

310

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CROSS-CORRELATION between LC OBS and LC EST

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Fig. A.12.7.c) GS29 - PRN 01 ( 24 1 1997) - [segment Ic]Auto Correlation of LC.OBS (Roo) and LC=EST (Ra.Cross Correlation between them (RoUnit: [cycles] 2

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station: GS29 (Ashtech) satellite: PRN 07

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314

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Fig. A.13.2 : Station: GS29 - Satellite: PRN 07Data acquisition date 24 1 1997Signal-to-Noise-Ratio (SNR) for LI and L2.

315

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Fig. A.13.3: Station: GS29 - Satellite: PRN 07- Data acquisition date 24 1 1997

The observed phase residual (LC.OBS) is compared with the

multipath phase error estimated from the SNR (LC_.EST)

Unit: [cycles]

316

0.2

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5000 10000Time (sec)

5000 10000Time (sec)

Fig. A.13.4 : Station: GS29 - Satellite: PRN 07- Data acquisition date 24 1 1997

LC.OBS and LCEST compared for t--0.0 - 1.4 10 4 sec

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Fig. A.13.5.a) GS29 - PRN 07 ( 24 1 1997) - [segment la]Phase residual LC-DIFF, determined as the differencebetween LCOBS and LCEST.Unit: [cycles]

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Fig. A.13.6.c) GS29 - PRN 07 ( 24 1 1997) - [segment lb]Auto Correlation of LC..OBS (R.) and LCEST E).Cross Correlation between them (R)

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x 104

station: GS29 (Ashtech) satellite: PRN 25

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326

x 10

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4.4 4.5 4.6 4.7 4.8 4.9 5Time (sec) x 104

Fig. A.14.4.a) GS29 - PRN 25 ( 24 1 1997) - [segment #1]Phase residual LCDIFF, determined as the differencebetween LC.OBS and LC.EST.Unit: [cycles]

329

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Fig. A.14.4.b) GS29 - PRN 25 (24 11997) - [segment #1]PSD of LCOBS, LCEST and LC..DIFF.

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10-'

=

f-4

e/m 100-J" 0

o

I

GS29 (Ashtech) PRN 25 - Califomia 24 1 1997

-6000 -4000 -2000 0 2000 4000 6000

-M -6000 -4000 -2000 0 2000 4000 6000

CROSS-CORRELATION between LC OBS and LC EST

1

0.5

-6000 -4000

Fig. A.14.4.c)

-2000time delay :Tau (sec)

2000 4000 6000

GS29 -PRN 25 ( 24 1 1997) - [segment #1]Auto Correlation of LCOBS (RPo) and LC.EST (Ree.Cross Correlation between them (Roe)Unit: [cycles] 2

331

8000

8000

-0.5

_1-8000 8000

segment 1

-8000

-I

-a - a

.......... .............. .. ..

-..................................... ............ ...........

GS29 (Ashtech) PRN 25: Phase Error

4.4 4.6 4.8 5Time (sec) x 10

COHERENCE OF LC OBS and LC EST

-1

frequency [Hz]

frequency [Hz]

CROSS-SPECTRAL Power Density

10" 10 10"2

frequency [Hz]

Fig. A.14.4.d) GS29 - PRN 25 (24 1 1997) - [segment #1]Auto Spectral Power Density of LC..OBS (So) and of

LC.EST (See). Cross PSD between them (Soe)

Unit: [cycles]2

Coherence function of LC..OBS and LCEST

332

0.2

-0.1

-0.2

10-1

Auto-Spectral Power Density :seg 1

"RESIDUAL" = difference LC Observed - LC Estimated

Time (sec) x 10'

o = LC OBSERVED - GS29 (Ashtech) 25 * = LC ESTIMATED - GS29 (Ashtech) 25

5 5.1 5.2 5.3 5.4 5.5 5.6 5.7Time (sec) .,

A IJ

Fig. A.14.5.a) GS29 - PRN 25 ( 24 1 1997) - [segment #2]Phase residual LC...DIFF, determined as the differencebetween LCOBS and LC.EST.Unit: [cycles]

333

: seg 2

GS29 (Ashtech) PRN 25: Phase Error

. ........... ....... ........... .....%

:A,•:.~i ,I :,

5 5.2 5.4 5.6x 10'

5.2 5.4 5.6x 104

5.5

. 5

Power Spectra Density: Segment 2

Mo 3

0-j2

o0 1CDCL

U-410-2

10

5.2 5.4 5.6Time [sec]

103

10-2

10- 2

x 10'

Fig. A.14.5.b) GS29- PRN 25 (24 1 1997) - [segment #2]Power Spectral Density of LCOBS, LCEST and LC..DIFF.Unit: [cycles] 2

334

¶i

0.2

-0.1

0.2

0.1

o

-0.1

0.1

0

-0.1

0',

..

......... ........

1.. . ... , :............ :: .......

".

-1

-1

-1

10

10

10

I Vi I >1111ii iI· \V···Ui·

.• :. :. :.. ..... .

I:: : ::: :11:111:.. ... ... :.:.:.:.:: .. . :::

,~ ,

·I ' """" ' ' """' ' " ";;'1

~· \I~· -·- --·-- ·-·-····-·- --·-- ·--·· ···--·· 1Lf ~

"" "'

I :;

-

I

.................... . . . . . . . . . . . .

L

10

.... . . . . i ....... ... ....

........................... ....

0.2

10.

...........................-

GS29 (Ashtech) PRN 25 - California 24 1 1997

-6000 -4000 -2000 0 2000 4000 6000

-4000 -2000 2000 4000 6000 804

CROSS-CORRELATION between LC OBS and LC EST

I I I Ii i i i ........... ..................... ..... ....... ..... .................... . .... .. ... ...

-6000 -4000 -2000time delay :Tau (sec)

2000 4000 6000 8000

Fig. A.14.5.c) GS29 - PRN 25 (24 1 1997) - [segment #2]Auto Correlation of LC..OBS (Ro~ and LC.EST (Re).

Cross Correlation between them (Ro)

Unit: [cycles] 2

335

MO

00

I0

00

S.

K0 -6000

w-J

0

-80

0.5

0

-0.5

_I

-8000-8000

segment 2M .

8000

00

GS29 (Ashtech) PRN 25: Phase Error

5 5.2 5.4 5.6Time (sec) x 10' frequency [Hz]

COHERENCE OF LC OBS and LC EST

V- V V ---V V

10-2frequency [Hz]

10- 1

CROSS-SPECTRAL Power Density

)-

frequency [Hz]

Fig. A.14.5.d) GS29 - PRN 25 ( 24 1 1997) - [segment #2]Auto Spectral Power Density of LC_OBS (Soo) and of

LC..EST (Se). Cross PSD between them (Soe)

Unit: [cycles] 2

Coherence function of LC.OBS and LCEST

336

0.8

o 0.6

o-

5 0.4U

0.2

n

10-4

Auto-Spectral Power Density :seg 2

·"''''"" ' ' """'· "''''·"1··.··. ·.·;.'.:: · · ·:··.·:-.' ~.·.:;'··· · · ·'····· ··· ······ · · -"··'···~..·..·.·. r ~·~~... r . .'. ~.'.:'.·rt

· '··· · ·

· ·· · · · · · · ·'····

· ·- · · ·'······ · · ·

· · ·- · ·· c-·-· · · · · · · · · ~···~····~·

'··· · · ·"····· · · ·'··· · · "'····· · · ·

-::· · · · I··:·:-:·-:·:i;"" ' ' """'

~a~t, ···

'

'

• o

10 :

"RESIDUAL" = difference LC Observed - LC Estimated

I.I I I I. I'""'~".. .. .. ......."...... .. ...... ...... ...... .. ... ....5.7 5.75 5.8 5.85 5.9 5.95 6 6.05 6.1 6.15 6.2

Time (sec)

o = LC OBSERVED - GS29 (Ashtech) 25 * = LC ESTIMATED - GS29 (Ashtech) 25

6.25x 10

5.7 5.75 5.8 5.85 5.9 5.95 6Time (sec)

6.05 6.1 6.15 6.2 6.25x 104

Fig. A.14.6.a) : GS29 - PRN 25 (24 1 1997) - [segment #3]Phase residual LCDIFF, determined as the differencebetween LC.OBS and LC.EST.Unit: [cycles]

337

0.3

0.2

0.1

0

-0.1

-0.2

U.;3

0.2

0.1

-0.1

-0.2

.. I I . . . . .

:seg 3

I

I

m

I

-·..... ..............................·

X

ALNY'

· · · · · ·

GS29 (Ashtech) PRN 25: Phase Error Power Spectra Density : Segm 32

0.2 .................... ... .. .C1 1.5 *

n 0.1 ........ a V, 00 -

x 10x 10 .

0.20.1

W 00-J -0.1

-0.2

1.50-J

CO 0.5

a

5.7 5.8 5.9 6 6.1 6.2 10-4 10-3 10- 2 10"-

x 10'

0.2u- 0.1

j -0.1-0.2

LL

1.5

1-'

a.

5.7 5.8 5.9 6 6.1 6.2 10-4 10"3 10-2 101Time [sec] x 10

Fig. A.14.6.b) : GS29 - PRN 25 (24 1 1997) - [segment #3]Power Spectral Density of LC.OBS, LCEST and LCDIFF.Unit: [cycles] 2

338

" -

........ .............. ... . I

· ·. · - ·- · · · ·- · ......... ......~~'

· · ··

---- · · · · · · · ·-- · ·-- ·--- ·-' · · · · ·- · ·----------- · ·"' -·'---·-

··-- ·

-·· · · · · · ·-· · ·

.. ~..·..·.===·~rl·\ ·:··'·~-`-~-~·'-· . · ·-'··'·~·'·'· '·'-'·"'· \ ' ' `~~"" ' ' ""'

'"· ' ' ""'

: · -. · s-~;;.-J; ''-r~-~-r---;---;r- -- I··.-;·.-.-- · · · · · · · · · ·

· ·. · . · I·---··· · · · · · · ·

·

.:. .. . .. . .. . .. . . . . . .. . . .:. . . .. . .... . . .. .

. . . . . . . ... . . ., . .··. ······ : · ·-·· ·· ·- -.· .... ...... -'............

..· .=.·. '... .:. ... ·.... :.. .. . .; -- l-. ·-i;. ic- ··.-.-..·...

GS29 (Ashtech) PRN 25 - Califomia 24 1 1997 segment 3

-4000 -2000 0 2000 4000

CROSS-CORRELATION between LC OBS and LC ESTI &I I

L..

I II I I

-2000 0time delay :Tau (sec)

2000 4000

Fig. A.14.6.c) GS29 - PRN 25 (24 1 1997) - [segment #3]Auto Correlation of LC.OBS (Roo) and LCF.ST (Re).

Cross Correlation between them (Roe)

Unit: [cycles] 2

339

IM

0O

000oI

-6-6000

-bUUU

-4000 -2000 0 2000 4000 6000

6000

1

0.5

0o

2 -0.50.9-I

-6000 -4000 6000· · · 1

- I

,

L

GS29 (Ashtech) PRN 25 : Phase Error

... . . . . . . ... . . . . . .... . . .. . ... . . . . . . . .

S- ` i. .. 1.

.. . .. . .. . . . . . . . . . . . . . . . .. ." ° '

.. . .. . . . . . . . . . . . . . . .. . . . . . . . i. . . .

5.7 5.8 5.9 6 6.1 6.2Time (sec)

40C

--30(

"20(

8W 10(

1

x 10'

COHERENCE OF LC OBS and LC EST

Auto-Spectral Pow Density :seg 3

0i

. 1 zii ! ! ii !; · · · · · ·:•i . .. ... , !i iii i i i:ii0 ... ." i :: :.1::::i .~ .. : .iii:.. ...f. .:.i.i:I :\:::: ! ::: :;::. : Ij

104 10- 10-2

frequency [Hz]

CROSS-SPECTRAL Power Density

103 10-2frequency [Hz]

Fig. A.14.6.d)

10-1 10" 10- 10-2frequency [Hz]

GS29 - PRN 25 (24 1 1997) - [segment #3]Auto Spectral Power Density of LC..OBS (Soo) and of

LCEST (S). Cross PSD between them (Soe)

Unit: [cycles] 2

Coherence function of LC_OBS and LC_EST

340

0 0W-0.1

-0.2

10

0.8

0.6

0.4

0.2

nO.

10- 1• 1 1. . . . . . . . . .

0.3

0.2

• °

I -

[

U10

. .. • ° . . . . .... .. .. , . . . ....

.- -..;;- . , .; .; .. ';'. . .

GPS "OBSERVED" Phase Residuals for: COSO (Ashtech) PRN 30 - California 23 1 1997

1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3GPS "ESTIMATED" Phase Residuals computed from the analysis of SNR variation x 10'

1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3Comparison LC OBSERVED vs LC ESTIMATED x 10

1 1.2 1.4 1.6 1.8 2Time (sec)

2.2 2.4 2.6 2.8 3x 10'

Fig. A.15.1: Station: COSO - Satellite: PRN 30Data acquisition date 23 1 1997

The observed phase residual (LCOBS) is compared with themultipath phase error estimated from the SNR (LC...EST)Unit: [cycles)

341

o 0.1wc- 0.05wUn 0

O -0.05- -0.1

I I i a i a a a i .t

.- ..... . . . . . .. .. .

... . . ... ..!.1, ""..

r • r"I I I I . I .

I I I I I I I I

I.................. ......... ................. ..............I i..... .-··'··~ ·················· ·5... .... ...........:..... i.......... .......................................................

0.10.05

0

-0.05-0.1

0.10.05

0

-0.05-0.1

... . ................................. ............... i ..------ --. ...

. .. ..

.

I I I i i I i , I I

I I I n ......

COSO (Ashtech) PRN 30 - Califomia 23 1 1997

1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2Time (sec) x 10'

[ I I -1

1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2Time (sec) x 104

Fig. A.15.2 : Station: COSO - Satellite: PRN 30Data acquisition date 23 1 1997LCOBS and LC.EST compared for t=1.0 - 2.0 10 4 sec

Unit: [cycles)

342

0.05

0

-0.05

-0.1

S. . . . .

FI. I I I I I I1

i

"RESIDUAL" = difference LC Observed - LC Estimated - 23 1 1997

1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2Time (sec) x 10

o = LC OBSERVED - COSO (Ashtech) 30 * - LC ESTIMATED - COSO (Ashtech) 30

1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2Time (sec) x 10'

Fig. A.15.3.a) COSO - PRN 30 (23 1 1997) - [segment 1]Phase residual LC..DIFF, determined as the differencebetween LCOBS and LC.EST.Unit: [cycles]

343

0.15

0.1

0.05

0

-0.05

-0.1

0.15

0.1

S0.05

w

o. -0.05-J

-0.1

COSO PRN 30 (23 1 1997): Phase Error

1.2 1.4 1.6 1.8x 10'

1.2 1.4 1.6 1.8

n10-le

0

Power Spectra Density

...

.... :: . . . ...... . . . . ....

; " ' : ; 5 " " " '1" . . ......'"v i " ' ?' """i' : :: ::

"\ "

:/: ::: :• (-,. :t•:,:-.·. -·--. . -Li - ! ! !•!ii?·

10

10 4

10-210

10-2

0-110

10- 1

x 10'

1 1.2 1.4 1.6Time [sec]

1.8 2x 10*

0.4

0.2

loe-3 -2

10- 10-~ 2

Frequency [Hz]

Fig. A.15.3.b) COSO- PRN 01 (23 11997) - [segment 1]PSD of LC.OBS, LC_..EST and LC.DIFF.

Unit: [cycles] 2

344

..........l....... .......... ....... .........l

......... .......................

........................ ....i......... ..

t -- ---- ---

0.10.05

0

-0.05-0.1

0.050

-0.05-0.1

. . . . .:.. . : . . . . .

0.10.05

0-0.05

-0.1

10- 1

- -- · -- --- ~- -·

........... ...... ,......... ....

..... .. .. .... .. . ...... ... .... .. ..

.......·...... ......:...................

1.2 1.4 1.6 1.8

. . ... . ..

. . . . - .

x

104

' i

z

I

x

10

4

· '

· ·

· ·... ,

· .· .

i

10 -3

..'AA

"'"

'

"'·.-. ·. ·. I·

· ·· ·

·-· ·

·.--- ·-· ·

· ·· ·

COSO (Ashtech) PRN 30 - California 23 1 1997 segment 1

0.5

0

-n r.

-1

-1 -_0. -U.b -U.4 -U.2 U U.Z U.4 U.b U.0 1

CROSS-CORRELATION b

T x 10

0.2

a: 0

00 -0.2

0CA

0-0.

-0.8 -0.6

Fig. A.15.3.c)

-0.4 -0.2 0 0.2 0.4 0.6 0.8 1time delay : Tau (sec)

COSO - PRN 30 (23 1 1997) - [segment 1]Auto Correlation of LC..OBS (R) and LC..EST (Re.Cross Correlation between them (Ro

Unit: [cycles] 2

345

.I I I I . . .. I..

0 0.2 0.4 0.6 0.8 1-0.8 -0.6 -0.4 -0.2

I-- - tI I

I I I I I

-1

x 10'

_ ·

4

-

-

-

,,P,·r ~ Rt•R-R3RRIAT(3 h~·~ twl~-·n LC -~ -1 n CI='"x

· · · · · · · ·i

A c

COSO (Ashtech) PRN 30 (23 1 1997): Phase Error0.1

0.05

0

-0.05

-0.11 1.2 1.4 1.6

Time (sec)

1

8

Uo

c')"1

1.8 2

x 104

COHERENCE OF LC OBS and LC EST

-1

frequency [Hz]

frequency [Hz]

CROSS-SPECTRAL Power Density

10" 10-" 10"frequency [Hz]

Fig. A.15.3.d) COSO - PRN 30 (23 1 1997) - [segment 1]Auto Spectral Power Density of LC_OBS (Soo) and of

LC...EST (See). Cross PSD between them (Soe)Unit: [cycles] 2

Coherence function of LCOBS and LC..EST

346

-I

10'

Auto-Spectral Power Density

0.10.05

0-0.05-0.1

0.10.05

0-0.05-0.1

GPS "OBSERVED" Phase Residuals for: COSO (Ashtech) PRN 30 - California 24 1 1997

.... ........ .....

.I

r I .. . . . I ................... ......... ............ ...... :....... ...- ...... ... . . ...

It s I III

1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3GPS "ESTIMATED" Phase Residuals computed from the analysis of SNR variation x 10

1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3Comparison LC OBSERVED vs LC ESTIMATED x 104

0.10.05

0-0.05-0.1

1 1.2 1.4 1.6 1.8 2Time (sec)

2.2 2.4 2.6 2.8

Fig. A.16.1: Station: COSO - Satellite: PRN 30Data acquisition date 24 1 1997The observed phase residual (LC.OBS) is compared with themultipath phase error estimated from the SNR (LCEST)Unit: [cycles]

347

I I __ I F

................... .. . .. . .. .. .. .. .. .. .

.......... .......... ...... I.. .......... .......... .......... ....................-... ... ... .... .. ... ..... ... ..... .... .. .... . ..... ... ... ... .. .. ...

I I I I I I

S... ..... ..... ..... .. .. ......... ..

.................. .... .... .

3

x 104

I I I I I I I I I

c

!I

COSO (Ashtech) PRN 30 - Califomia 24 1 1997

1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3Time (sec) x 10

0.15

0.1

0.05

0

-0.05

-0.1

1 1.2 1.4 1.6 1.8 2Time (sec)

2.2 2.4 2.6 2.8

Fig. A.16.2 : Station: COSO - Satellite: PRN 30Data acquisition date 24 1 1997LCOBS and LCEST compared for t=1.0 - 2.0 10 4 sec

Unit: [cycles]

348

IIII II. .......... ........ .: ......... .......... .......... ....... _" .... ..... . ... :. II . ..

I -

3x 10

-----

"RESIDUAL" - difference LC Observed - LC Estimated - 24 1 1997

1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9Time (sec) x 10'

o = LC OBSERVED - COSO (Ashtech) 30 * = LC ESTIMATED - COSO (Ashtech) 30I. I I II I~ I I I I

1 1.1 1.2 1. 1.4 1. 1.6 1.7 1.8 1.9 21 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2

Time (sec) x 104

Fig. A.16.3.a) COSO - PRN 30 (24 1 1997) - [segment 1]Phase residual LC...DIFF, determined as the differencebetween LCOBS and LCEST.Unit: [cycles]

349

0.15

0.1

0.05

0

-0.05

-0.1

0.15

0.1

0.05

00 -0.05

-0.1-0.1

* ... I 1

_ · · _· · ·

i

COSO PRN 30 (24 1 1997): Phase Error

0.1cn 0.050 0

-3 -0.05

-0.1

1 1.2 1.4 1.6 1.8

0.10.05

0-0.05

-0.1

x 10'103

n1.2 1.4 1.6 1.8

0.1u. 0.055 0

0 S-0.05-0.1

x 10'

1 1.2 1.4 1.6Time [secJ

10-4

1.8 2

x 10'

10-2

10-3 10-210

Frequency [Hz]

Fig. A.16.3.b) COSO-PRN 01 (24 1 1997) - [segment 1]PSD of LC.OBS, LC.EST and LCJDIFF.Unit: [cycles] 2

350

I..I.. . . . . . . . . . . .. . ...........r .3 . .... ...4 -. .............. .: ..............

...... ... ·.. . Lir .. .. . . . . . . . . . . .

..

: ..

I: :,. .....:1:'

." . · r..~.~ .I......

0- 1

10- 1

-1

Power Spectra Density

I

.. . . ... . . . .. . . . .. . . .

.. ... .......... ... ...... ..... .... ..... ... ... .... ...... ... ...

X

104

" ' ':: : : : : '' ': ' ' "':':

. . ... ... . . . .. .. . . . ...

. . . . .. . . . .

. ... 1...:.... = ·- t.. ....... . . .. ·....• ::.;L~ .....

... . . . . ., . .. . . ... . . .

. . . . . . . . . . . . . . . . . . . . . . . . ... ........... ........................

x

104

· ·

· '

t .·. ·. ·. ·h· ·· ·· ·

· · ·

· ·

10 -4

COSO (Ashtech) PRN 30 - Caifomia 24 1 1997 segment 1et

-0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1

-0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1

CROSS-CORRELATION between LC OBS and LC EST x 10'

-0.8 -0.6 -0.4 -0.2

Fig. A.16.3.c)

0 0.2 0.4 0.6 0.8 1time delay :Tau (sec)

COSO - PRN 30 ( 24 1 1997) - [segment 1]Auto Correlation of LC.OBS (Roo) and LC..EST .

Cross Correlation between them (Ro)

Unit: [cycles] 2

351

S1O

-J

0o

I0

I1-1-1

0.5

-0.5

I1

I I I I I I I I I

I I I II ~ l~I-1l

1

x 10'

<-1

-

COSO (Ashtech) PRN 30 (24 1 1997): Phase Error

1 1.2 1.4 1.6Time (sec)

1.8 2

x 104

COHERENCE OF LC OBS and LC EST1500

t' 1000

0

" 500CL

n

-1

frequency [Hz]

Fig. A.16.3.d)

frequency [Hz]

CROSS-SPECTRAL Power Density

10 10- 2

frequency [Hz]101

COSO - PRN 30 (24 1 1997) - [segment 1]Auto Spectral Power Density of LC.OBS (So) and of

LC..EST (Se). Cross PSD between them (Soe)

Unit: [cycles] 2

Coherence function of LCOBS and LC.EST

352

Auto-Spectral Power DensityI

10"

Appendix B

353

tIA

b'

Observed Phase Estimated Corrected Difference of Variance Decrease ofStation Satellite Set Number Residual Multipath Phase Residual before and after Variance afterCode Number of Variance Phase Error Variance Multipath Correction Correction

Samples VarianceA 2 A2 2 A2 A2

site: GOBS GEST (TDIFF TOBS - NDIFF

ASIA PRN N [%]ASIA PRN A(5) 10^(5) 1A(-) 10A(-.5) 1%[cycles]' [cycles] 2 [cycles] [cycles?)

MANA 26 la 132 877.42 1021.73 699.35 178.07 ± 93.05 20.30

lb 151 387.43 312.33 218.61 168.82 ± 34.97 43.57

2a 175 93.67 49.15 130.88 -37.22 ± 9.95

2b 232 40.90 20.75 40.38 0.52 ± 3.30 1.28

2c 133 202.96 119.46 243.15 -40.19 + 24.32

MANA 28 la 190 89.90 30.48 89.04 0.86 + 6.92 0.96

lb 106 269.83 211.86 218.56 51.27 + 33.40 19.00

2a 100 489.41 404.55 301.72 187.70 ± 56.21 38.35

2b 101 78.29 43.92 48.96 29.33 ± 8.56 37.47

2c 144 82.45 82.84 73.01 9.44 ± 9.17 11.45

2d 101 812.35 882.72 535.67 276.68 ± 90.63 34.06-ii i1

t•t•H

t.

U'

Measurement Noise Multipath Noise Estimation NoiseStation Satellite Set Number Variance Variance VarianceCode Number of

Samples ^ 2 ^ 2 A 2

site: GMN GMPN GEN

ASIA PRN N 10^(-5) 10^(-5) 10^(-5)

[cycles]' [cycles]2 [cycles] 2

MANA 26 la 132 227.51 599.90 421.83

lb 151 146.86 240.58 71.75

2a 175 87.70 5.97 43.18

2b 232 30.26 10.64 10.12

2c 133 163.32 39.64 79.83

MANA 28 la 190 74.23 15.67 14.81

lb 106 138.26 131.56 80.29

2a 100 193.29 .. 296.13 108.43

2b 101 41.67 36.63 72.91

2c 144 36.31 46.14 36.70

2d 101 232.65 579.70 303.02

Observed Phase Estimated Corrected Difference of Variance Decrease ofStation Satellite Set Number Residual Multipath Phase Residual before and after Variance afterCode Number of Variance Phase Error Variance Multipath Correction Correction

Samples Variance

site:A 2 A 2 A 2 A 2 ^2

ASIA PRN N ooas Esr OCDIFF COBS - (DI

10^(-5) 10^(-5) 10^(-5) 10^(-5)

[cycles]' [cycles]' [cycles]2 [cycles])

KKAU 16 2a 171 471.22 55.94 547.85 -76.62 ± 25.18

2b 267 188.44 42.20 131.44 57.01 ± 9.39 30.25

2c 154 320.32 392.58 206.61 113.71 ± 26.26 35.50

KKAU 20 2a 160 101.39 93.30 183.08 -81.69 ± 14.98

2b 158 287.34 505.17 176.52 110.82 ± 16.30 38.57

KKAU 22 1 118 207.93 403.47 141.21 66.72 ± 19.36 32.09

2 206 561.25 242.98 755.63 -194.38 ± 50.46

3 452 29.34 44.01 47.07 -17.73 .± 2.52

,-3

0

0v

WE.

tb30,

rl.

GPS MultipathStation Satellite Set Number Measurement Noise Multipath Noise Estimation NoiseCode Number of Variance Variance Variance

Samples

site: ^ 2 A 2 A 2

ASIA PRN N GMN MPN (EEN

10A(.5) 10^(-5) 10A(-5)

[cycles]' [cycles]' [cycles]'

KKAU 16 2a 171 481.57 -10.34 66.28

2b 267 138.84 49.60 -7.40

2c 154 67.17 253.14 139.43

KKAU 20 2a 160 95.59 5.80 87.50

2b 158 -20.65 307.99 197.17

KKAU 22 1 118 -27.16 235.09 168.37

2 206 536.95 24.30 218.68

3 452 16.20 13.14 30.87- -i

Observed PhaseResidualVariance

^ 2

10^(-5)

[cycles]'

,m

L0n

EstimatedMultipath

Phase ErrorVariance

A 2

GE~r

10^(-5)

[cycles]'

2459.69

306.73

95.13

83.64

160.31

597.31

255.62

CorrectedPhase Residual

Variance

A 2ODIFF

10^(-S)

[cycles]'

1089.03

413.08

124.95

165.37

192.40

297.77

105.95

Difference of Variancebefore and after

Multipath Correction

A 2 2GoBS - GDIFF

10^(-5)

[cycles]'

995.22 + 130.22

117.71 + 49.58

3.29 ± 15.51

-88.10 ± 14.71

68.19 ± 18.15

99.82 + 21.43

56.66 ± 5.11

Decrease ofVariance after

Correction

[%]

47.75

22.18

2.56

26.17

25.11

34.84

2084.25

530.79

128.23

77.28

260.59

397.59

162.60

StationCode

site:

LIGO

00280036

00280036

00280036

SatelliteNumber

PRN

09

15

25

Set

1I

2

3

4

1

2

Numberof

Samples

N

208

160

126

124

286

256

254

IA

LA'w0cr

GPS MultipathStation Satellite Set Number Measurement Multipath EstimationCode Number of Noise Noise Noise

Samples

site: ^ 2 ^ 2 A 2

LIGO PRN N OMN MP-N (EN

10^(-5) 10A(5) 10^(-5)

[cycles]' [cycles]' [cycles] 2

0028 09 1 208 356.79 1727.45 732.240036

0028 15 1 160 318.57 212.22 94.510036

2 126 79.02 49.21 45.92

3 124 79.50 -2.23 8.59

4 286 146.34 114.25 46.06

0028 25 1 256 49.03 348.56 248.750036

2 254 6.46 156.14 99.48

EstimatedStation Satellite Set Number Observed Phase Multipath Corrected Difference of Variance Decrease ofCode Number of Residual Phase Error Phase Residual before and after Variance after

Samples Variance Variance Variance Multipath Correction Correction

data:A 2 A 2 A 2 A 2 ^2

LIGO PRN N OoBS GEST O'DIFF OOBS - ODIFF [%]

10^(-5) 10^(-5) 10^(-5) 10^(-5)

[cycles]' [cycles]2 [cycles]? [cycles] 2

LI 09 1 208 280.00 200.00 210.00 70.59± 2.35 25.38

L2 09 1 208 420.00 81.89 280.00 140.00± 2.20 34.18

GPS Multipath MultipathStation Satellite Set Number maesurement Variance estimation noiseCode Number of noise noise Variance

SamplesLIGO A 2 A 2 A 2

PRN N (MN (MPN EN

Ll 09 1 208 140.00 130.00 63.33

L2 09 1 208 310.00 110.00 -30.80

EstimatedStation Satellite Set Number Observed Phase Multipath Corrected Difference of Variance Decrease ofCode Number of Residual Phase Error Phase Residual before and after Variance after

Samples Variance Variance Variance Multipath Correction Correction

site:^ 2 ^ 2 ^ 2 A 2 ^2

South PRN N GOBs (EST (DIFF GOBS - (DIFFCalif [%]10^(.5) 10^(-5) 10^(5S) 10^(5)

[cycles]' [cycles]' [cycles]) [cycles]'

COSE 01 la 170 81.25 96.49 210.63 -12938 + 14.94

lb 332 32.14 115.13 139.01 -167.88 + 6.24

Ic 224 547.12 1576.49 525.23 21.89 + 84.43 4.00-I

COSE 07 2a 233 86.71 195.98 352.02 -26531 + 20.21

2b 215 772.21 1910.36 695.44 76.73 ± 88.90 9.94

COSE 25 1 211 66.46 75.87 153.24 -86.78 + 10.17

2 212 48.01 192.05 176.02 -128.01 + 7.63

3 179 238.26 880.10 394.16 -155.86 + 47.53

ipH0\

it

oCt,•

GPS MultipathStation Satellite Set Number Measurement Noise Multipath Noise Estimation NoiseCode Number of Variance Variance Variance

Samples

site: ^ 2 ^ 2 A 2

South PRN N GMN (MPN GENCalif Calif 0 ^ (-5) 10 ^ (-5) 10 ^ (-5)

[cycles]' [cycles]2 [cycles]2

COSE 01 la 170 97.70 -16.45 112.94

lb 332 28.01 4.12 111.01

Ic 224 252.07 799.19 777.30

COSE 07 2a 233 121.38 -34.66 230.64

2b 215 -222.26 1008.77 929.60

COSE 25 1 211 71.91 -5.46 81.33

2 212 15.99 32.02 160.03

3 179 -155.86 362.12 517.88

EstimatedStation Satellite Set Number Observed Phase Multipath Corrected Difference of Variance Decrease ofCode Number of Residual Phase Error Phase Residual before and after Variance after

Samples Variance Variance Variance Multipath Correction Correction

site:A 2 A 2 A 2 A 2 A 2

South PRN N Goas OGEST DIFF GOBS - GDIFFCalif [%10A(-5) 10A(.5) 10A(-5) 10A(.5)

[cycles]' [cycles]' [cycles]' [cycles])

GS29 01 la 173 50.94 56.28 90.32 -39.38 + 7.46

lb 332 106.06 2.95 114.65 -8.59 ± 1.97

Ic 219 635.20 1046.25 529.37 105.83 + 33.70 16.66

GS29 07 2a 234 30.19 7.75 43.50 -13.32 + 2.10

2b 211 797.58 1221.09 631.62 165.96 ± 48.85 20.81

GS29 25 1 208 123.95 59.26 176.77 -52.82 ± 11.76

2 212 178.50 4.62 192.37 -13.87 ± 4.01

3 173 319.50 297.42 130.28 189.22 + 22.96 59.22

GPS MultipathStation Satellite Set Number Measurement Noise Multipath Noise Estimation NoiseCode Number of Variance Variance Vairance

Samples

site: ^ 2 ^ 2 A 2

South PRN N - (MPN (EN

Calif10^(-5) 10^(-5) 10^(-5)

[cycles] 2 [cycles]' [cycles]2

GS29 01 la 173 42.49 8.44

lb 332 108.88 -2.82 5.77

Ic 219 59.16 576.03 470.21

GS29 07 2a 234 32.97 -2.78 10.53

2b 211 104.05 693.53 527.56

OS29 25 1 208 120.73 3.22 56.04

2 212 183.24 -4.62 9.25

3 173 76.18 243.32 54.10- - -

C,

0w

U.

EstimatedStation Satellite Set Number Observed Phase Multipath Corrected Difference of Variance Decrease ofCode Number of Residual Phase Error Phase Residual before and after Variance after

Samples Variance Variance Variance Multipath Correction Correction

site:^ 2 ^ 2 A 2 A 2 A 2

South PRN N Goss EST MGDIFF (OBS - ODIFFCalif [%J10^(-5) 10^(-5) 10^(-5) 10^(.5)

[cycles]2 [cycles]' [cycles]) [cycles]'

COSO30 1 300 64.53 18.22 68.98 -4.46 ± 3.75

23 1 97

COSO30 1 300 98.09 15.68 82.52 15.56 ± 4.16 15.86

24 197

GPS Multipath MultipathStation Satellite Set Number maesurement Variance estimation noiseCode Number of noise noise Variance

SamplesSouth ^ 2 ^ 2 A 2Calif PRN N GM N GOMPN OEN

COSO30 1 300 57.65 6.88 11.34

23 1 97

COSO30 1 300 82.46 15.62 0.06

241 97

366

Appendix C

367

FFTobs est diff.m

t% This program computes the Power Spectral Density of the time seriesS LC_ OBS, LC_EST and LC DIFF

clear

load SAT ESTload SAT _OBS

Nl-length(SAT OBS(:,1));N2-length(SAT_EST(:,1));

index-0;

hours-18;minutes-45;

epoch - SAT OBS(:,i);time _sec= (epoch-l)*30+hours'3600+minutes*60;SAT_0BS(:,l)-time sec;

for j-i:Nlfor i-1:N2

if SAT0OBS(j, 1)-SATEST (i, 1)index-index+l;SAT D 3(index,1)-SAT OCBS(j,1);SAT D 3(index,2)-SAT OBS(j,4)-SAT_EST(i,7);SAT 0 1(index,1)-SAT OBS(j, 1);SAT E 2(index,1)-SAT EST(i,1);SAT 0 1(index,2)-SATC BS(j,4);SAT E 2 (index, 2)-SAT EST (i, 7);

end

endend

SAT 1-SAT 0 1;SAT 2-SAT E 2;SAT 3-SAT D 3;

n-length(SAT 2(:,l));dt-30;m-n/2;

SATE (r,l)-SAT 2(1,1);SAT _O (r, 1)-SAT 2(1,1);SAT D(r,1)-SAT 2(1,1);

SAT 0(r,2)-SAT 1(1,2);SAT E(r,2)-SAT 2(1,2);SAT D(r,2)-SAT 3(1,2);

368

~--·-IIPPIII~IPIl~··~IPPPIPPPIIIIIIIPIIIP

for ind-2:nr=r+1;SAT 0(r,1)-SAT 2(ind,1);SAT E (r, 1)-SAT 2 (ind, 1);SAT D(r,1)-SAT 2(ind,1);

SAT O(r,2)-SAT_ (ind,2);SATE (r, 2) -SAT 2 (ind, 2);SAT D(r,2)-SAT 3(ind,2);

if SAT 2(ind,1)>SAT 2(ind-1,1)-+dtt miss-SAT 2(ind)-SAT 2(ind-1);n miss-t miss/dt-1;for i-1:nmiss+l

SAT O(r,1)-SAT 2(ind-1,1) +dti;SAT E(r,1)-SAT 2(ind-1,1)+dt*i;SAT D(r,1)-SAT 2(ind-, 1)+dt*i;

SAT 0(r,2)-SAT 1(ind-1,2)+i*(SAT_1 (ind,2)-SAT 1(ind-1,2))/ (n_miss+1);SAT E(r,2)-SAT-2(ind-1,2)+i*(SAT 2(ind,2)-SAT 2(ind-1,2))/(nmiss+l);SAT D(r, 2) -SAT 3(ind-i,2)+i*(SAT_3(ind,2)-SAT 3(ind-1,2))/ (n_miss+l);

if i<n miss+lr-r+l;end

end

end

end

N-r;

dt-30;Ny-n/2+1;fNy - 1/(2*dt);T - n*dt;df-fNy/(Ny-1);f-[0 :df: fNy];

norm E -( SAT E(:,2)-mean(SAT E(:,2)) );norm 0 ( SAT_0(:,2)-mean(SAT_0(:,2)) );norm DIFF-( SATD(:,2)-mean(SAT D(:,2)) );

FTEST - fft(norm E);FTOBS - fft(norm 0);FT DI-F - fft(norm DIFF);

? FT EST-FT EST.*conj(FTEST)./n;P FT OBS-FT OBS.'conj(FT_OBS)./n;P_FTDIFF-FTDIFF. *conj (FTD-) ./n;

figure (1)clf

subplot (3,2,1)plot(SAT0O(:,1), SAT_O(:,2),'-.')holdgridylabel(' LC OBS ')title(' COSE (Trimble) PRN 25: Phase Error')

369

subplot (3, 2, 2)se.milogx(f,PFTOBS(l:Ny)*dt,'-.');holdgridylabel(' PSD of LC OBS')title ('?ower Spectra Density: Segment 3')

subplot (3, 2, 3)plot (SATE(:, 1l), SATE(:,2))holdgridylabel('LC EST ')

subplot (3, 2, 4)semilogx(f,PFTEST(1:Ny) dt);holdgridylabel(' PSD of LC EST')

subplot (3,2,5)plot (SAT D(:, 1), SAT D(:,2))holdgridylabel('LC DIFF')xlabel('Time [sec]')

subplot (3, 2, 6)semilogx(f,PFT_DIFF (l:Ny)dt);holdgridylabel(' PSD of LC DIFF')

return

370

% Auto Cross CORR..m

This program computes the Auto correlation of the two time series% LCOBS, LCEST and their Cross correlation

clear

load SAT ESTload SAT OBS

clear

load SAT ESTload SAT OBS

Nl-length (SAT OBS (:,));N21length(SAT EST(:,1));

index-0;

hours-18;minutes-45;

epoch - SAT_OBS(:,l);time sec= (epoch-) *30+hours*3600+minutes*60;SAT OBS (:, 1)-timesec;

for j-l:Nlfor i-L:N2

if SATOBS(j,l)-SAT EST(i,1)index-index+l;SATD_3(index,l)-SAT_OBS(j,1);SATD_3(index,2)-SAT OBS(j,4)-SAT.EST(i,7);SAT 0 _l(index,l)-SATOBS(j,1);SAT E 2(index,l)-SAT EST(i, 1);SAT 0 1 (index,2)-SAT OBS (j, 4);SAT E_2 (index, 2) -SAT EST (i, 7);

end

endend

SAT 1=SAT 0 1;SAT 2=SAT E 2;SAT_3-SAT D 3;

n-length (SAT2 (:, 1));dt-30;m-n/2;

371

r-1;

SAT E(r,1)-SAT 2(1,1);SAT-0 (r, 1)-SAT 2(1,1);SAT D(r, 1)-SAT 2(1,1);

SAT O(r,2)-SAT 1SAT E (r,2)-SAT 2SAT D(r,2)-SAT 3

(1,2);(1,2);(1,2);

for ind-2:nr-r+1;SAT O(r,1)-SAT 2(ind, 1);SAT E(r, 1)-SAT 2(ind, 1);SAT D (r, 1)-SAT 2 (ind, 1);

SAT 0(r, 2)-SAT1 (ind, 2);SAT E(r,2)-SAT 2 (ind,2);SAT D(r,2)-SAT 3(ind,2);

if SAT 2(ind,1)>SAT 2(ind-1,1)+dtt miss-SAT 2(ind)-SAT 2(ind-1);n miss-t miss/dt-1;for i-l:n miss+l

SAT_ (r,l)-SAT 2(ind-1,1)+dt'i;SATE(r,1)-SAT 2(ind-!,l)+dt*i;SAT D(r,1)-SAT 2(ind-1,1)+dt*i;

SAT 0(r,2)-SAT 1(ind-1,2)+i*(SAT_1(ind,2)-SAT_ (ind-1,2))/(n miss+1);SAT_ (r, 2)-SAT 2(ind-1,2)+i(SAT_2 (ind, 2)-SAT_2 (ind-1, 2))/(nmiss+l) ;SATD (r,2)-SAT3 (ind-1,2)+i"(S-AT 3(ind,2)-SAT_3(ind-1,2))/(nmiss+1);

if i<n miss+1r-r+i;end

end

end

end

N-r;

figure (I)clf

subplot(4,1,1)x-SAT 0(:,2);c-xcorr (x,'coeff');Tau-N*30;L--Tau+30 :30 :Tau-30;plot(L',c)holdgridylabel('Auto-Corr LC OBS')title('COSE (trimble) ?RN 25 - California 23 1 1997 segment 1')

subplot (4, 1,2)y-SAT_E ( :,2);c-xcorr (y, 'coeff');Tau-N *30;

372

L--Tau+30 :30 :Tau-30;plot (L', c)holdgridylabel('Auto-Corr LC EST')

subplot (2, 1, 2)x-SAT 0(:,2);y-SAT E(:,2);c-xcorr (x, y, 'coeff');Tau=N*30;L--Tau+30: 30: Tau-30;plot (L', c)holdgridylabel(' Cross-Corr : R_o_e(Tau)')xlabel(' time delay : Tau (sec) ')title(' CROSS-CORRELATION between LC OBS and LC EST ')return

373

% SP CORR obs est.m.m

This program computes the AUTO Spectral Density of the two time seriesLC OBS, LC EST and their CROSS Spectral Density from the correlationfunctions.

clear

format long

load SAT ESTload SAT_0BS

N1-length(SAT OBS (:,1));N2-length(SATEST (:, ));

index-0;

hours-18;minutes-45;

epoch - SATCBS(:,I);time sec- (epoch-1)*30+hours*3600+minutes*60;SAT _OBS(:,l)-time sec;

for j-l:N1for i-I:N2

if SAT OBS(j,1)--SAT EST(i,l)index-indexi1;SAT D 3(index,1)-SAT OBS(j,1);SAT D 3(index,2)-SATOBS (j,4)-SAT ST(i,7);SAT 0 1(index, 1)-SATOBS(j, 1);SAT E 2(index,1)-SAT_ ST(i,1);SAT 0 1(index,2)-SAT OBS(j,4);SAT - 2(index,2)-SAT-EST(i,7);

end

endend

SAT 1-SAT 0 1;SAT 2-SAT E 2;SAT 3-SATD_3;

n-length(SAT_2(:,1));dt-30;m-n/2;

r-l;

SAT E(r,1)-SAT 2(1,1);SATO (r, 1) -SAT 2 (1,1);SAT D(r,1)-SAT 2(1,1);

SAT 0(r,2)-SAT 1(1,2);SAT _(r,2)-SAT 2(1,2);

374

SAT D(r,2)-SAT_3(1,2);

for ind-2:nr-r+1;SAT O(r, 1)-SAT 2(ind,1);SAT E(r, 1)-SAT 2(ind, 1);SAT D(r, 1)-SAT 2(ind, 1);

SATO o(r,2) SAT_ (ind,2);SAT E(r,2)-SAT 2(ind,2);SAT D(r, 2)-SAT 3(ind,2);

if SAT 2(ind,1)>SAT 2(ind-1,1)+dtt miss-SAT 2(ind)-SAT 2(ind-1);n miss-t miss/dt-1;for i-l:nmiss+1

SAT 0(r,1)-SAT 2(ind-1,1)+dt*i;SAT E (r, 1) -SAT 2 (ind-1, 1) +dt*i;SAT D(r,1)-SAT 2(ind-1,1)+d:*i;

SAT 0 (r,2)-SAT _1(ind-1, 2)+i' (SAT 1(ind, 2)-SAT 1(ind-1, 2))/(n_miss+l);SATE(r,2)-SAT 2(ind-1,2)+i*(SAT_2 (ind,2)-SAT 2(ind-1,2))/(nmiss+1);SAT_D(r, 2) -SAT_3(ind-1, 2)+i' (SAT3 (ind, 2)-SAT3 (ind-1, 2) )/(nmiss+1);

if i<n miss+lr-r+1;end

end

end

end

N-r;

x-SAT 0(:,2);y-SAT_E(:,2);

xc-xcorr (x, y, 'coeff');aco-xcorr (x, 'coeff');ace-xcorr(y, 'coeff');

n-index;dt-30;Ny-n/2+1;fNy - 1/(2*dt);T - n*dt;df-fNy/ (Ny-1);f-[0:df:fNy];

FT OBS - fft(aco);FT EST - fft(ace);FT CROSS-fft (xc);

P FT OBS-FT OBS.'conj(FT_OBS);P FT EST-FT EST.*conj(FTEST);P-FT-CROSS-FT CROSS.*conj (FT_CROSS);

Rft-real (FT CROSS);Ift-imag(FTCROSS);

375

figure (1)clfsubplot (2,2,1)plot(SAT O(:,l), SAT O(:,2),'-.')holdplot(SATE(:,l), SAT_E(:,2))gridylabel(' LC OBS / LC EST')xlabel(' Time (sec) ')title(' COSE (trimble) PRN 25 - segm 3: Phase Error')

subplot (2,2,2)semilogx(f,PFTOBS(1:Ny),'-.');holdsemilogx(f,P_ FT EST(1:Ny));gridylabel(' So_o(f) and S_e_e(f)')title('Auto-Spectral Power Density')xlabel('frequency [Hz]')

subplot(2,2,4)semilogx.(f, PFT_CROSS(1:Ny));holdgridylabel('AMPLITUDE of S_o_e(f)')title('CROSS-SPECTRAL Power Density')xlabel(' frequency (Hz]')

subplot (2,2,3)space for : COHERENCEreturn

376

Coherence obs est.m

This program computes theLC OBS, LC EST.

Coherence Function of the time series

clear

format long

load SAT ESTload SAT-OBS

N1-length(SAT OBS(:,1));N2-length(SATEST(:,1));

index=O;

epoch - SAT OBS(:,1);time sec- (epoch-l) *30+hours*3600+minutes*60;SAT OBS(:,l)-timesec;

for j-i:Nlfor i-1:N2

if SATOBS(j, 1)-SAT EST(i,1)index-index+l;SAT D 3(index,1)-SAT_ OBS(j,1);SAT D_3(index, 2)-SAT.OBS(j, 4)-SAT..EST(i, 7);SAT 0 1(index,1)-SAT OBS (j,1);SATE 2 (index, 1)-SAT EST (i, 1);SAT_O_1(index,2)-SAT_OBS(j,4);SAT E_2 (index, 2) -SAT EST (i, 7);

end

endend

SAT 1-SAT 0 1;SAT 2-SAT E 2;SAT_ 3SAT D 3;n-length(SAT2(:,1));dt-30;m=n/2;

r-1;

SAT E(r, 1)-SAT 2(1,1);SAT O(r,1)-SAT 2(1,1);SAT D(r, 1) -SAT_2(1,1);

SAT 0(r,2)-SAT 1(1,2);SAT E(r,2)-SAT 2(1,2);SAT D(r,2)-SAT 3(1,2);

377

IP1IILI11IPIIIIIPIPIPIIPIPPIII~PPPIIIIII

~I~III~LIIPIIIIDI-PIUIIIPPIIPIII~I~IICII

PPIPIIP~PIPIIPIIPIIIIIIIPOIIP~·PIIIIIIII

for ind-2:nr-r+1;SATO(r, 1) SAT 2(ind, 1);SAT E(r,1)-SAT 2(ind,l);SAT D(r, 1)-SAT 2(ind, 1);

SAT_O (r,2)SAT_ (ind,2);SAT E(r,2)-SAT_2(ind,2);SAT_D(r,2)-SAT 3(ind,2);

if SAT 2(ind,1)>SAT 2(ind-1,1)+dtt miss-SAT 2(ind)-SAT_2(ind-1);n miss-t miss/dt-1;for i-l:n miss+l

SAT_O(r,l)-SAT 2(ind-1,1)+dt*i;SAT E(r, l)SAT 2(ind-1,1)+dt*i;SAT D(r,1) SAT 2(ind-1,1)+dt*i;

SAT _O(r,2)-SAT 1(ind-1,2)+i*(SAT_1(ind,2)-SAT 1(ind-1,2))/(n miss+1);SAT E(r,2)-SAT 2(ind-1,2)+i (SAT 2(ind,2)-SAT 2(ind-1,2))/(nmiss+1);SATD (r,2)-SAT3 (ind-1,2)+i*(SAT_3(ind,2)-SAT3 (ind-1,2))/((nmiss+1);

if i<n miss+lr-r+1;end

end

end

end

m-r;dt-30;

clear SATESTclear SAT OBS

SAT OBS-SAT 0;SATEST-SAT E;

ns-input('NUMBER OF SUBSECTIONS =')nps-round ((m-1) /ns);x-[0:dt: (nps-l)'dt];df-l./((nps-l)*dt);f-df* [0:round(nps/2)-1];

lambda(2:nps/2)-1./f(2:nps/2);lambda (1) -2*lambda (2);logla-logl0(lambda);T - (nps-1)*dt/2;

nstart-1;nstop-nps;

normOBS- (SATOBS (:,2)-mean(SAT_OBS( :,2)) )./std( SATOBS(:,2));normEST- (SAT EST(:,2)-mean(SAT_EST(:,2)) )./std( SAT EST(:,2));

norm OBS - SAT OBS(:,2);norm EST - SAT EST(:,2);

for j-l:ns

378

0-norm_0BS(nstart:nstop);FT OBS- fft(O);R FT OBS-real(FT OBS);I FTOBS-imag(FT_0BS);AOBS(:,j)-R FT OBS.*R FT OBS/T+I FT OBS.I _FTOBS/T;E=nor mEST(nstart:nstop);FT EST - fft(E);R FT EST-real(FT EST);I FT EST-imag(FT_EST);AEST(:,j)-R FT EST. *RFTEST/T+IFTEST.I FTEST/T;A OBS_EST(:,j)-R_FT_EST.*R FT OBS/T+I FT EST.*I FT OBS/T;nstart-nstop+l;nstop-nstop+nps;

end

if ns -- 1A OBS bar-A OBS';A EST bar-A EST';A 0BS EST bar-A _BS EST';

elseA OBS bar-sum(A OBS')/ns;A ESTbar-sum(A EST' )/ns;A OBS EST bar-sum(AOBS EST')/ns;

end

coherence-(A OBS EST bar.*A OBS EST bar)./(A OBS bar. *AEST bar);for i-l:nps

if coherence(i)--l;coherence(i) -- 0.9999999;

endend

figure (1)

subplot (2,2,3)pf(2:nps/2)- f(2:nps/2);pf(1)= pf(2)/2;semilogx(pf,coherence(1 :nps/2),'d');holdgrid'semilogx(pf,coherence (:nps/2));xlabel(' frequency (Hz]')ylabel('Coherence ')title('COHEPELNC OF LC OBS and LC EST')

return

379

Statistical Analysis.m

This performes the statistical analysis of the time seriesLC_OBS, LCEST and LC DIFF.

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clear

format long

load SAT ESTload SATOBS

N1-length(SATOBS (:,1));N2-length(SAT EST(:,1));

index-0;hours-18;minutes-45;

epoch - SAT OBS(:,l);time sec- (epoch-l) *30+hours*3600+minutes*60;SAT OBS(:,l)-time_sec;

for j-1:N1for i-1:N2

if SAT OBS(j,l)-SAT EST(i,1)index-index+l;SAT D 3(index,l)-SAT OBS(j,1);SAT_ D 3(index,2)-SAT OBS(j,4)-SAT EST(i,7);SATO (index, 1)-SATOBS(j, );SAT E 2(index, )-SAT EST(i, );SAT_O_1(index,2)-SATOBS(j,4);SAT E 2(index,2)-SAT EST(i,7);

end

endend

SAT 1-SAT_0O1;SAT 2-SAT_ 2;SAT_3-SAT D 3;

n-length (SAT_2 (:,1));dt-30;m-n/2;

r-1;

SAT E(r,l)-SAT 2(1,1);SAT- (r, 1) -SAT 2 (1, 1);SAT D(r, 1)SAT 2(1,1);

SAT 0(r,2) SAT 1(1,2);SAT E(r,2)-SAT 2(1,2);SAT D(r,2)-SAT_3(1,2);

380

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