1 recall the theoretical jargon: l1 pseudorange – c/a or p(y) l2 pseudorange - p(y) or c2 l5...
TRANSCRIPT
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RECALL THE THEORETICAL JARGON:
• L1 pseudorange – C/A or P(Y)• L2 pseudorange - P(Y) or C2• L5 pseudorange - ignore for now.• L1 Phase• L2 Phase (can come from either P(Y) or C2 stream)• L5 Phase - ignore• Doppler - ignore!• Signal to noise ratio (SNR)
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NOW YOU NEED TO KNOW THE RINEX JARGON
• L1 pseudorange – C/A = C1• L1 pseudorange – P(Y) = P1• L2 pseudorange - P(Y) = P2• L2 pseudorange - C = C2• L1 Phase = L1• L2 Phase =L2• Signal to noise ratio (SNR) = S1 and S2
Note L1 and L2 are really the names of the GPS frequencies.But RINEX uses the same names for the phase data. This is really
unfortunate - but it is the way it is.
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RINEX FILES
RINEX is a generic term - it refers to a kind of data format. It is ALWAYS ascii. (BINEX is a binary version).
o: Observation d: Observation (compressed or Hatanaka)
n: Navigation filem: Meteorological data fileg: GLONASS Navigation file
h: Geostationary GPS payload nav mess fileb: Geostationary GPS payload broadcast
datac: Clock files
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RINEX observation file o is the standard observation file
d is the compressed observation file
Many people call the d file Hatanaka format after Yuki Hatanaka who defined it. You need an extra program to convert compressed to normal observation file. See this link for more details
http://www.gsi.go.jp/common/000045517.pdf
http://igscb.jpl.nasa.gov/igscb/data/format/rinex210.txt
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2.11 OBSERVATION DATA G (GPS) RINEX VERSION / TYPEteqc 2012Jun6 gpsops 20120921 00:08:49UTCPGM / RUN BY / DATE 30.0000 INTERVAL 1 1 WAVELENGTH FACT L1/2 7 L1 L2 P1 P2 C1 S1 S2 # / TYPES OF OBSERVLinux 2.4.21-27.ELsmp|Opteron|gcc -static|Linux x86_64|=+ COMMENT 2.10 OBSERVATION DATA GPS COMMENTsoc2rnx ver 1.20 gpsops 21-Sep-2012 00:08:49COMMENTS1, if present, is the SNR for the C/A data stream on L1. COMMENT SNR is mapped to RINEX snr flag value [1,4-9] COMMENT SNR: >316 >100 >31.6 >10 >3.2 >0 bad=0 COMMENTL1 & L2: 9 8 7 6 5 4 1 COMMENTGGN USNO OBSERVER / AGENCYKW-0201 AOAD/M_T NONE ANT # / TYPE -1248596.2520 -4819428.2840 3976506.0340 APPROX POSITION XYZ 0.0000 0.0000 0.0000 ANTENNA: DELTA H/E/NRT920013101 ASHTECH Z-XII3T IL01-1D04-MCF-12MX REC # / TYPE / VERSAMC2 MARKER NAME40472S004 MARKER NUMBER
Every RINEX file has a header - they are important!
There are rules for how these files are written and read. Useful to know that this format (and these rules) are defined by people that use Fortran.
Every RINEX file has a header
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2.11 OBSERVATION DATA G (GPS) RINEX VERSION / TYPEteqc 2012Jun6 gpsops 20120921 00:08:49UTCPGM / RUN BY / DATE 30.0000 INTERVAL 1 1 WAVELENGTH FACT L1/2 7 L1 L2 P1 P2 C1 S1 S2 # / TYPES OF OBSERVLinux 2.4.21-27.ELsmp|Opteron|gcc -static|Linux x86_64|=+ COMMENT 2.10 OBSERVATION DATA GPS COMMENTsoc2rnx ver 1.20 gpsops 21-Sep-2012 00:08:49COMMENTS1, if present, is the SNR for the C/A data stream on L1. COMMENT SNR is mapped to RINEX snr flag value [1,4-9] COMMENT SNR: >316 >100 >31.6 >10 >3.2 >0 bad=0 COMMENTL1 & L2: 9 8 7 6 5 4 1 COMMENTGGN USNO OBSERVER / AGENCYKW-0201 AOAD/M_T NONE ANT # / TYPE -1248596.2520 -4819428.2840 3976506.0340 APPROX POSITION XYZ 0.0000 0.0000 0.0000 ANTENNA: DELTA H/E/NRT920013101 ASHTECH Z-XII3T IL01-1D04-MCF-12MX REC # / TYPE / VERSAMC2 MARKER NAME40472S004 MARKER NUMBER
Every RINEX file has a header - they are important!
If you are making RINEX files, it is very impolite to leave out the receiver position.For completeness, always include S1 and S2 (many geodesists leave it out - for no good reason).
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2.11 OBSERVATION DATA G (GPS) RINEX VERSION / TYPEteqc 2012Jun6 gpsops 20120921 00:08:49UTCPGM / RUN BY / DATE 30.0000 INTERVAL 1 1 WAVELENGTH FACT L1/2 7 L1 L2 P1 P2 C1 S1 S2 # / TYPES OF OBSERVLinux 2.4.21-27.ELsmp|Opteron|gcc -static|Linux x86_64|=+ COMMENT 2.10 OBSERVATION DATA GPS COMMENTsoc2rnx ver 1.20 gpsops 21-Sep-2012 00:08:49COMMENTS1, if present, is the SNR for the C/A data stream on L1. COMMENT SNR is mapped to RINEX snr flag value [1,4-9] COMMENT SNR: >316 >100 >31.6 >10 >3.2 >0 bad=0 COMMENTL1 & L2: 9 8 7 6 5 4 1 COMMENTGGN USNO OBSERVER / AGENCYKW-0201 AOAD/M_T NONE ANT # / TYPE -1248596.2520 -4819428.2840 3976506.0340 APPROX POSITION XYZ 0.0000 0.0000 0.0000 ANTENNA: DELTA H/E/NRT920013101 ASHTECH Z-XII3T IL01-1D04-MCF-12MX REC # / TYPE / VERSAMC2 MARKER NAME40472S004 MARKER NUMBER
Every RINEX file has a header - they are important!
This means there will be 7 columns of observations, L1 (phase) in the first column, L2 phase in the second, and so on. Since only 5 columns can fitin a line, they have to write the 6th and 7th column on the next line.
Rows are saved for satellites. An example on the next page.
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top line is year, month, day, hour, minute, second
Then number of satellites and their names. G means GPS, R is glonass,and M is Galileo. If there a blank instead of a letter, it means it is a GPS satellite. You cannot assume people will use the G - believe me. GPS came first, so it got to be blank.
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Then number of satellites and their names. G means GPS, R is glonass,and M is Galileo. If there is no letter, it means it is a GPS satellite.
In this example, there are 9 satellites. They are all GPS satellites.
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These are the data for PRN 29. Remember the first two columns are phase (L1 and L2) and then P1, P2, and C1. Last are S1 and S2.
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What are the units? Don’t guess - Look it up!
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What does F14.3 mean?
L1 L2 P1 P2 C1
What is P2?
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RINEX Nav Message – clock model
+----------------------------------------------------------------------------+ | TABLE A4 | | NAVIGATION MESSAGE FILE - DATA RECORD DESCRIPTION | +--------------------+------------------------------------------+------------+ | OBS. RECORD | DESCRIPTION | FORMAT | +--------------------+------------------------------------------+------------+ |PRN / EPOCH / SV CLK| - Satellite PRN number | I2, | | | - Epoch: Toc - Time of Clock | | | | year (2 digits) | 5I3, | | | month | | | | day | | | | hour | | | | minute | | | | second | F5.1, | | | - SV clock bias (seconds) | 3D19.12 | | | - SV clock drift (sec/sec) | | | | - SV clock drift rate (sec/sec2) | | +--------------------+------------------------------------------+------------+
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RINEX Nav file the header is boring
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RINEX Nav file
16The rest of the numbers refer to Keplerian elements - (not needed yet)
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Where to get RINEX observation data?
In Europe, I prefer EUREF
http://www.epncb.oma.be
In the US, UNAVCO
http://facility.unavco.org/data/dai2/app/dai2.html#
or CDDIShttp://cddis.nasa.gov
It can be frustrating to find data that are not archived in these larger data centers.
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Where to get RINEX navigation data?
I only use navigation quality orbits for my current research,and for years I have gotten these files at SOPAC at garner.ucsd.edu
%!/bin/cshftp -in garner.ucsd.edu << eofuser anonymous [email protected] pub/rinex/${year}/${day}mget auto*quiteofwhere year is, e.g. 2013, day is day of year, 305
It returns auto3050.13.Z, which is unix compressed, so you need to say
uncompress auto3050.13.Z
There is a smarter command (wget) to pick up files, but I will leave that for you to figure out!
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There are lots of places to find precise orbits. Just google IGS precise orbits and you will find a link to somewhere. They DO NOT use RINEX. They have their own format, which is called sp3.