3.1.1. sh_gamit

Once you have edited appropriately the template files, you can start the processing from within the experiment directory by giving sh_gamit simply the 4-character code for the project or subnet (termed “experiment”) and a range of days to process:

$ sh_gamit -expt emed -d 2018 034 035 036 >& sh_gamit.log

The sh_gamit command is executed at the project-directory level. The time span can also be specified using -s {<start_day>} {<stop_day>} to indicate a range of consecutive days, or -r {<days>} to indicate that you want to process a single day {<days>} before the current date. If you plan to process data from more than GPS, use -gnss {<sys>}, where sys is G for GPS, R for Glonass, C for Beidou, E for Galileo, and I for IRNSS. You may also override some of the parameters specified in process.defaults, e.g.:

-orbit {<type>}

Type of orbit (e.g. igsf igsr igsu codm gfzm siof; see sh_get_orbits; default igsf)

-eops {<name>}

EOP series to be used (usno [default], usnd)

-sessinfo

Sampling interval, #epochs, start time (HH MM) (e.g. 30 2880 0 0 )

-copt

List of files to compress in the day directory (default x, k, autcln.out, d)

-dopt

List of files to delete from the day directory (default C-files only)

-pres ELEV

Plot phase vs elevation and as skyplots (default no)

-nopngs

Do not create PNG files of sky plots (default is to create from PostScript)

-yrext

Add year prefix to names of day directories

-netext {<char>}

Add suffix (character) to names of day directories

-noftp

Don’t try to ftp any data from outside your system (default is to ftp)

Most of the time the parameters may be omitted in favor of the values you have specified in process.defaults for the whole experiment. The overrides are useful, however, if you wish to test the effect of processing a day with a different orbit, EOP table, or session length, or for different GNSS, in which case you can create a second directory for the same day by appending a character to its name (e.g., -netext t to create 034t/). When -gnss is specified, the day directories will automatically be named with the GNSS code as the extent (e.g. 034E/ for Galileo). Finally, you may launch sh_gamit from anywhere on the system by specifying the full path name of the processing directory with -dir {<path>}. When the script runs, it will write to the screen a record of each step, which you may choose to redirect to a file (e.g., >& sh_gamit.log). Examining the screen log together with the comments and source code in ~/gg/com/sh_gamit and the GAMIT.fatal file, will allow you to identify the point and reason for failure should that occur. When processing of each day is completed, sh_gamit will send a mail message to you (mailto in process.defaults) giving the number of stations used, the rms of the one-way phase residuals for the two best and two worst stations from the autcln postfit summary file, the nrms values from the Q-file, the number of ambiguities resolved, and a list of any large adjustments to station coordinates. These statistics will let you know whether you need to examine the GAMIT output further for possible reprocessing.