modernization of the philippine geodetic reference … pgrs/02_gatr...modernization of the...

Engr. Ronaldo C. Gatchalian, MGITChief, Geodesy Division – NAMRIA

Poolside Pavilion, Dusit Thani Manila26 May 2017

Modernization of the Philippine Geodetic Reference System

(PGRS)

OUTLINE

1. Positioning, Luzon and PRS Frame

2. Reference Systems and Frames

3. WGS84 vs ITRF

4. Global Geodetic Reference Frame

5. Modernization of the PGRS

Modernization of the Philippine Geodetic SystemDusit Thani Manila, 26 May 2017

Geographic Position provides location based on a reference system, not only of people and places, but more importantly of events.

Geographic Position

φ = 14°32'7.43"Nλ = 121° 2'26.78"E


Positioning

• During the early times, the position of a point can be obtaineddirectly by observing the stars

• Astronomical positioning was used to determine the datum originof a country or region


Luzon Datum of 1911The Geodetic Datum for all surveying and mapping activities in

the Philippines until 1988; use the Clarke 1866 Ellipsoid and the

Triangulation Network as “Reference Frame”

A “local” network of triangulation points used as reference in establishing project controls for cadastral, topographic and hydrographic surveys


Philippine Reference System of 1992 (PRS92)A new reference system for all surveying and mapping activities in

the Philippines from 1992 to present; use the Clarke 1866 Ellipsoid

with the GCPs establish by GPS as the “Reference Frame”

A “local” network of geodetic control points used asreference in establishing project controls for cadastral,topographic and hydrographic surveys


Reference Systems, Datum and Projections

Reference Systems

ITRS

WGS84

PRS92

Datum

Geodetic Datum

Geocentric Datum

Luzon 1911

Projections

Universal Transverse Mercator -UTM

Phil Transverse Mercator - PTM

1:5,000&Larger

1:10,000&Smaller

Cadastre


Reference System • Reference System is the complete conceptual definition of how a coordinate system is

formed • It defines the origin and the orientation of fundamental planes or axes of the system• It also includes the underlying fundamental mathematical and physical models

Source: Satellite Geodesy by Günter Seeber; Physical Geodesy by Dr. Bernhard Hofmann-Wellenhof


Reference Frame• Reference Frame means the practical realization of a reference

system through observations• It consists of a set of identifiable fiducial points on the sky (e.g. stars,

quasars) or on Earth’s surface (e.g. fundamental stations)

Source: Satellite Geodesy by Günter Seeber

WGS84 FrameITRF

LUZON 1911

PRS92


WGS84 vs ITRF• WGS84 reference frame was established in 1987 and realized through

a set of 11 TRANSIT (Doppler) station (later became GPS Tracking stations)coordinates in XYZ worldwide

• Data from these stations and five GPS Operational Control Segmentstations are used to generate precise GPS orbit and clock estimatesfor all satellites

WGS84 RF is not accessible; you cannot connect to it but only thru GNSS Satellites

WGS 84 Station Coordinate Updates

Name Implementation date ITRF Epoch Accuracy

GPS Broadcast NGA Precise

Orbits Ephemeris

WGS 84 1987 1 Jan 1987 1-2 meters

WGS 84 (G730) 29 Jun 1994 2 Jan 1994 1994.0 10 cm/component rms

WGS 84 (G873) 29 Jan 1997 29 Sep 1996 1997.0 5 cm/component rms

WGS 84 (G1150) 20 Jan 2002 20 Jan 2002 2001.0 1cm/component rms

WGS 84 (G1674) 8 Feb 2012 7 May 2012 2005.0 <1cm/component rms

WGS 84 (G1762) 16 Oct 2013 16 Oct 2013 2005.0 <1cm/component rms

Source: NGA.STND.0036_1.0.0_WGS84, 2014


WGS84 vs ITRF

• International Terrestrial Reference Frame (ITRF) was established in1988 and realized through a combination of GNSS, VLBI, SLR andDORIS station coordinates in XYZ (with 1-mm sigma) worldwide

• Constantly updated due to evolving instruments and data increase,the latest being ITRF2014

ITRF is accessible; you can connect to it through International GNSS Service ; http://www.igs.org/

VLBI – Very Long Baseline InterferometrySLR – Satellite Laser RangingDORIS - Doppler Orbitography and Radiopositioning Integrated by Satellitehttp://itrf.ensg.ign.fr/tech.php


Global Geodetic Reference Frame (GGRF)

“generic term for a framework which allows users to precisely determine and express locations on the Earth, as well as to quantify changes of the Earth in space and time” – UN GGIM


• GGRF is fundamental for monitoring changes of the Earth• It is also fundamental for mapping, navigation and universal

timing


A GGRF is needed for monitoring these changes

Changes of the Earth e.g. climate change, plate movements, land subsidence & uplift, sea level rise, etc. are not just local events! ---- They are

global!


Accuracy Different applications require different positional accuracy

Millimeter

CentimeterDecimeter

Meter


February 26, 2015

UN General Assembly Resolution No. 69/366‘A call for the adoption of a global geodetic reference frame for sustainable

development’


Modernization of the Philippine Geodetic Reference System (PGRS)

To develop and provide access to an authoritative geodetic reference system aligned with a global geodetic reference frame,

that will serve as the common reference for all surveying and mapping activities in the country

Major Objective:


Modernization of the Philippine Geodetic Reference System (PGRS)

Components :

Densification of PageNET

And Alignment to ITRF

Development and Maintenance of the

Philippine Geodetic Vertical Datum 2020

Strengthening of core competencies, R&D and IEC

-- Establish 200 AGS-- Develop Deformation Model-- Compute ITRF Coordinates of PageNet-- Re-Observe 3000 GCPs (Zero, 1st & 2nd )

-- Develop PGVD 2020-- Densify Gravity Stations-- Re-compute PGM2014

-- Train NAMRIA Staff-- Massive IEC Campaign-- Amendment of existing laws (PRS92 to PGD2016)-- R&D on Modernization


Timeline

Migration to Geocentric Datum

Mapping and Geodesy Branch, National Mapping and Resource Information Authority

2016 2017 2018 - 2019 2020 onwards

Densification of the Philippine Active Geodetic Network

Re-observation of geodetic control points

Computation of ITRF solution for PageNET in Philippine Geocentric Datum 2016 (PGD2016)

Network Adjustment and development of transformation parameters

Development, validation and refinement of deformation model

Amendment of

enabling law

Research & Development on Modernization of PGRS

Revision of surveying and related regulations

Capacity building and IEC campaigns

Preparation and publication of technical manuals and guidelines

Development and Maintenance of the Philippine Geodetic Vertical Datum 2020 (PGVD2020)


Proposed Stations by 2025 - 200 AGS


Connection to ITRF

Connect PageNET to ITRF and compute coordinate solutions using Bernese Software


ITRF/IGS Stations around Philippines

Download RINEX data from IGS and compute coordinate solutionshttp://www.igs.org/


Re-compute PGM2014 Preliminary geoid model – Philippine Geoid Model 2014- Based on satellite, aerial and terrestrial gravity data;

in partnership with DTU-Space and US NGA- Can estimate MSL elevations using GNSS

geoid – a hypothetical shape of the earth that approximates the mean sea level and is used to estimate surface elevations

Note : PGM2016 is available for download at namria.gov.ph; Featured Site- Philippine Geoid Model

PGM2016

PGM2014--PGM2016


Preferred research topics

Implications of datum change to land titling

Transformation strategy : national, provincial or micro blocks?

Coordinates change cycle in a dynamic datum

Should the BMs be “maintained” after the adoption of PGVD 2020

What projection should be used : UTM or PTM

Basic principle of VLBI

τ c

radio source

b

Accomplishments

Re-observed passive geodetic control points and computed ITRF coordinates

Zero order – 65

1st and 2nd order -- 300

Benefits

A ‘world-class’ geodetic reference system that is consistent, accurate, up-to-date and interoperable with global geospatial information

Account for geodynamics in our surveys

Benefits

Surveyors can use AGS as reference in GNSS RTK survey of LOT Parcels “nationwide” without transforming

Lot buyers can verify lot parcels (in ITRF)using handheld GPS or Smartphone

Surveyors can estimate MSL elevations using GNSS and the PGM2016 or later version

What do we have now?

A static PRS92 does not account for geodynamics Inconsistent with global reference systems (e.g. Enhanced WGS84 and ITRF) Incapable of monitoring earth changes

PRS92 Map

WGS84 Map

ITRF/WGS84φ = 14°32'7.43"Nλ = 121° 2'26.78"E

PRS92φ = 14°32‘6.57"Nλ = 121° 2'25.23"E

Accuracy

Accurate and up to date position data (or changes in position) provides important inputs to:

DRRM Resource management Development planning Emergency response Earth monitoring and Earth

Studies

What do we have now?

Philippine Reference System of 1992 (PRS92)

At the time of establishment, PRS92 is the best fit reference

system for the country. However, PRS92 is a static and local

system.

Although PRS92 have corresponding WGS84 coordinates, our WGS84 is localand is not tied to the GGRF

What needs to be done?

39 Active Stations PGM 2014 Densify active geodetic stations to 200 Re-observe 2700 1st & 2nd order GCPs Revise EO 45 Develop, validate and maintain a deformation

model Development and maintenance of PGVD2020 Capacity building IEC campaigns

modernization of the philippine geodetic reference … pgrs/02_gatr...modernization of the...

Documents