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1 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.

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Presentation on theme: "1 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."— Presentation transcript:

1 1 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)

2 2 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.

3 3 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 file m: Meteorological data file g: GLONASS Navigation file h: Geostationary GPS payload nav mess file b: Geostationary GPS payload broadcast data c: Clock files

4 4 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

5 OBSERVATION DATA G (GPS) RINEX VERSION / TYPE teqc 2012Jun6 gpsops :08:49UTCPGM / RUN BY / DATE INTERVAL 1 1 WAVELENGTH FACT L1/2 7 L1 L2 P1 P2 C1 S1 S2 # / TYPES OF OBSERV Linux ELsmp|Opteron|gcc -static|Linux x86_64|=+ COMMENT 2.10 OBSERVATION DATA GPS COMMENT soc2rnx ver 1.20 gpsops 21-Sep :08:49COMMENT S1, 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 COMMENT L1 & L2: COMMENT GGN USNO OBSERVER / AGENCY KW-0201 AOAD/M_T NONE ANT # / TYPE APPROX POSITION XYZ ANTENNA: DELTA H/E/N RT ASHTECH Z-XII3T IL01-1D04-MCF-12MX REC # / TYPE / VERS AMC2 MARKER NAME 40472S004 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

6 OBSERVATION DATA G (GPS) RINEX VERSION / TYPE teqc 2012Jun6 gpsops :08:49UTCPGM / RUN BY / DATE INTERVAL 1 1 WAVELENGTH FACT L1/2 7 L1 L2 P1 P2 C1 S1 S2 # / TYPES OF OBSERV Linux ELsmp|Opteron|gcc -static|Linux x86_64|=+ COMMENT 2.10 OBSERVATION DATA GPS COMMENT soc2rnx ver 1.20 gpsops 21-Sep :08:49COMMENT S1, 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 COMMENT L1 & L2: COMMENT GGN USNO OBSERVER / AGENCY KW-0201 AOAD/M_T NONE ANT # / TYPE APPROX POSITION XYZ ANTENNA: DELTA H/E/N RT ASHTECH Z-XII3T IL01-1D04-MCF-12MX REC # / TYPE / VERS AMC2 MARKER NAME 40472S004 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).

7 OBSERVATION DATA G (GPS) RINEX VERSION / TYPE teqc 2012Jun6 gpsops :08:49UTCPGM / RUN BY / DATE INTERVAL 1 1 WAVELENGTH FACT L1/2 7 L1 L2 P1 P2 C1 S1 S2 # / TYPES OF OBSERV Linux ELsmp|Opteron|gcc -static|Linux x86_64|=+ COMMENT 2.10 OBSERVATION DATA GPS COMMENT soc2rnx ver 1.20 gpsops 21-Sep :08:49COMMENT S1, 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 COMMENT L1 & L2: COMMENT GGN USNO OBSERVER / AGENCY KW-0201 AOAD/M_T NONE ANT # / TYPE APPROX POSITION XYZ ANTENNA: DELTA H/E/N RT ASHTECH Z-XII3T IL01-1D04-MCF-12MX REC # / TYPE / VERS AMC2 MARKER NAME 40472S004 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 fit in 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.

8 8 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.

9 9 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.

10 10 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.

11 11 What are the units? Don’t guess - Look it up!

12 12

13 13 What does F14.3 mean? L1 L2 P1 P2 C1 What is P2?

14 14 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) | |

15 15 RINEX Nav file the header is boring

16 16 RINEX Nav file 16 The rest of the numbers refer to Keplerian elements - (not needed yet)

17 17 Where to get RINEX observation data? In Europe, I prefer EUREF In the US, UNAVCO or CDDIS It can be frustrating to find data that are not archived in these larger data centers.chived in these large

18 18 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/csh ftp -in garner.ucsd.edu << eofuser anonymous pub/rinex/${year}/${day}mget auto*quiteof where year is, e.g. 2013, day is day of year, 305 It returns auto Z, which is unix compressed, so you need to say uncompress auto Z There is a smarter command (wget) to pick up files, but I will leave that for you to figure out!

19 1918 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.


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