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This is an example of preparing RINEX data, station metadata and approximate
coordinates from raw files and field logs for input to GAMIT.

We provide a raw file from a Trimble receiver and the accompanying log from the
North San Francisco Bay 2018 survey (https://doi.org/10.7283/BB35-CW22).

1. Read the log sheet and determine the site ID, receiver type and serial
   number, antenna type and serial number, antenna height during measurement.

2. Build commands for translation of raw file to RINEX 2.
   a. This is a Trimble file, so translate to "dat" format first.
   b. Translate to RINEX using teqc.

3. Read metadata into a station.info file.

4. Calculate an approximate position in GAMIT/GLOBK "l"-file format.


Answers:

1. Site ID: B468
   Receiver type: TRIMBLE R7 (check for consistency with IGS standard codes at
                  [1])
   Receiver serial number: 0220413532
   Antenna type: TRM57971.00 (check for consistency with IGS standard codes at
                  [1])
   Antenna serial number: 1441040534

2.a. runpkr00 -g -d b4682121.t01
2.b. teqc -O.r "M. Floyd (MIT)" -O.o "Funning/Swiatlowski" -O.ag "University of California, Riverside" -O.mo B468 -O.rt "TRIMBLE R7" -O.rn 0220413532 -O.at "TRM57971.00     NONE" -O.an 1441040534 +obs b4682121.18o -nav b4682121.18n -tr d b4682121.dat

   Now create a processing directory and move the RINEX file to a rinex/ sub-
   directory to be ready for processing, e.g.

   mkdir -p ~/rinex_test/2018/rinex/
   mv -i b4682121.18o ~/rinex_test/2018/rinex/

3. From the main processing directory, run sh_setup to copy fundamental files:

   cd ~/rinex_test/2018/
   sh_setup -yr 2018

   From the tables/ sub-directory, read the RINEX header into station.info:

   cd tables/
   sh_upd_stnfo -files ../rinex/b4682121.18o

   We will be left with a copy of ~/gg/tables/station.info plus the information
   from the B468 RINEX file header, assuming the site ID "B468" does not clash
   with anything already in the default ~/gg/tables/station.info.

4. Check https://igs.org/network for a nearby IGS site with known accurate
   coordinates in ~/gg/tables/igb14_comb.apr. QUIN is a reasonable choice for an
   IGS site in northern California. So let's download a RINEX 2 file for that
   site with which we can use sh_rx2apr, which only accepts RINEX 2 files:

   sh_get_rinex -archive cddis -yr 2018 -doy 212 -sites quin -rx2

   We also need to download a global navigation file:

   sh_get_nav -archive cddis -yr 2018 -doy 212

   Now we can do the approximate position calculation:

   sh_rx2apr -site b4682121.18o -nav b4682121.18n -ref quin2120.18o -apr ~/gg/tables/igb14_comb.apr

   We are left with a file called b468.apr, which contains the approximate
   coordinates for B468 in the correct format for GAMIT/GLOBK. The content of
   this file could be added to a general file along with other sites, with a
   file name of your choice (say expt.apr), then you can define
   "set aprf = expt.apr" in tables/process.defaults after running sh_setup in
   your processing directory.


[1] https://files.igs.org/pub/station/general/rcvr_ant.tab


  Michael Floyd (2021-08-09, MIT)

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