1. Automatic Processing with GAMIT
sh_gamit

2. Overview Motivation for sh_gamit an automatic processing script
runs GAMIT from RINEX files to H-files
How to set up sh_gamit
Running sh_gamit
Getting input correct makes runs more robust
Options in sh_gamit
User controls
28-Dec-18
GAMIT/GLOBK Tutorial 2

3. Motivation for sh_gamit
Increase in amount of GPS data
requires autonomous processing
GAMIT uses many files
sh_gamit manages them automatically
Successful with both continuous and campaign data
28-Dec-18
GAMIT/GLOBK Tutorial 2

4. What sh_gamit does
Checks tables (e.g. polar motion/UT1) for valid time range
Creates any directories that are needed.
Begins execution in the processing directory.
Get new tables by ftp if needed
Checks orbit files by ftp if needed
28-Dec-18
GAMIT/GLOBK Tutorial 2

5. What sh_gamit does (2)
Finds raw data files and translates them into RINEX format using teqc
Finds RINEX-format data files
Gets any missing files from the ftprnx entries with ftp
Creates a daily processing directory
Creates links in day directory to data files
Executes GAMIT run in day directory
28-Dec-18
GAMIT/GLOBK Tutorial 2

6. What sh_gamit does (3)
Plots one-way phase residuals and converted to images in GIF format
optional
GIF files are much smaller than postscript files
Updates processing history file
28-Dec-18
GAMIT/GLOBK Tutorial 2

7. What sh_gamit does (4)
Sends an message to you (not Simon!) with important summary information
number of sites
disk space remaining
best and worse RMS scatters
RMS fit from GAMIT runs
sites with large or no adjustments
28-Dec-18
GAMIT/GLOBK Tutorial 2

8. What sh_gamit does (5)
Compresses, archives or deletes intermediate files as selected by the user.
Begins processing next day’s data
Continues until fatal error or all requested days are processed.
28-Dec-18
GAMIT/GLOBK Tutorial 2

9. What sh_gamit does not do
Estimate velocities
The dishes
Think
28-Dec-18
GAMIT/GLOBK Tutorial 2

10. Basic example sh_gamit -d 1998 240 -orbit SIOF -expt emed -eops usno
process GPS data from day 240 of 1998 (Aug 28)
use any data in the local rinex directory
ftp data for sites specified by the user
optionally scan multiple directories to find data
use Final orbit estimate from Scripps Institution of Oceanography (SIO)
use EOP data from US Naval Observatory (USNO) [IERS Bulletin A]
Name the run “emed"
identify files
select data
28-Dec-18
GAMIT/GLOBK Tutorial 2

11. Running sh_gamit List options sh_gamit -help
Select days of data to process
-d yr days
where yr and days are the data to be processed e.g., -d
-s yr d1 d2
where d1 is start day and d2 is stop day to be processed e.g
-r day
where day is number of days before current date.
28-Dec-18
GAMIT/GLOBK Tutorial 2

12. sh_gamit options -expt
4 char name of experiment/solution being run [Default expt]
-orbit
Type of orbit to use. [Default SIOF]. Optional second argument gives the day-of-year for the orbit if not the same as processing day
-orbt
4 char ID for orbit files. [Default 4 char extracted from the orbit selected]
-eops
Name of EOP series to use. (bull_b, bull_a, etc.) [Default usno]
28-Dec-18
GAMIT/GLOBK Tutorial 2

13. sh_gamit options (2) -sessinfo
Session - sampling interval, number of epochs, start time (default )
-rx_doy_plus n
Search RINEX file names this many days into the future for current-day data
-rx_doy_minus n
Search RINEX file names this many days into the past for current-day data
-xsite list
List of sites to be excluded from the processing.
28-Dec-18
GAMIT/GLOBK Tutorial 2

14. sh_gamit options (3) -netext <char>
add network suffix <char> to day directories. i.e. 035r
-yrext
add year prefix to day directories. Ie 1997_053
-pres
Plot gamit residuals as skyplots <Y/N/E>. YES, NO, ELEV. [Default N]
-nogifs
Do NOT create skyplot GIF graphics files
28-Dec-18
GAMIT/GLOBK Tutorial 2

15. sh_gamit options (4) -mailto -copt [file types]
Compress remaining files for each dayserve when d [Default x k autcln.out]
-aopt [file types]
Copy the specified files for each day to the directory specified by –archivepth
-dopt [ file types]
Delete specified files after processing each day. [Default c]
-mailto
Name of user and machine to send results summary. (e.g.,
28-Dec-18
GAMIT/GLOBK Tutorial 2

16. sh_gamit options (5) -snrres
Calculate theoretical phase residuals from SNR. Requires raw data or RINEX with valid SNR values.
-noacc
Do not exclude satellites base on accuracy codes in the .sp3 file. [Default exclude]
-xver char
1-character x-file version (6th character of x-file). [Default is single-digit year]
-noftp
Use this option if no ftp download connections are available.
28-Dec-18
GAMIT/GLOBK Tutorial 2

17. sh_gamit options (6) -remakex Y/C/N
Y - Remake x-files without checking.
C - Remake x-file if orbit and session.info are incompatible and all RINEX files are available [Default C]
N - Don't remake x-files under any circumstances
28-Dec-18
GAMIT/GLOBK Tutorial 2

18. sh_gamit options (summary)
Most of the sh_gamit options are not normally used and are related to processing old GPS data or reprocessing 'failed' days.
Main options will be used in tutorial
28-Dec-18
GAMIT/GLOBK Tutorial 2

19. Before running sh_gamit
Create and fill templates directory
cd expt; cp -r ~/gg/templates .
Modify your files
cd expt/templates
edit templates/process.defaults
edit templates/sites.defaults
Create and fill "local" data directories
mkdir rinex
mdir raw
Ready to go
28-Dec-18
GAMIT/GLOBK Tutorial 2

20. process.defaults Normally only needs a little modification:
Default mailto address
Change directories where rinex and raw data may be found
Change the paths to:
gs (ghostscript)
convert (ImageMagik program to convert postscript to gif images).
These changes could be made permanently at each institution. They depend on machine setup)
28-Dec-18
GAMIT/GLOBK Tutorial 2

21. sites.defaults
File specifies other sites to be used in processing and how sites should be treated.
Format:
site expt options
expt is 4-character code for experiment
options given below
Main options:
ftprnx - ftp Rinex data
ftpraw - ftp raw dat
28-Dec-18
GAMIT/GLOBK Tutorial 2

22. Options in sites.defaults
localrx
Used to name sites that should be used from local rinex directories. If given only these sites are processed from the found files
xsite
Used to name sites that should not be used or not used for certain time spans
xstinfo
Ignore this site while automatically updating station.info file after successful solution
If a site is not in this list, then information about the antenna type and height will be extracted from the RINEX file
28-Dec-18
GAMIT/GLOBK Tutorial 2

23. How high was that antenna?
If the station.info file is absent from the tables directory, then sh_gamit will use the header information from the RINEX file
The file called guess_rcvant.dat will be used to translate the entries in the RINEX file to codes that GAMIT knows.
If this fails, then GAMIT will stop 'fatally'
Antenna height errors can be corrected downstream in GLOBK, but errors in identifying the antenna type can not be corrected (phase center variations)
28-Dec-18
GAMIT/GLOBK Tutorial 2

24. Controlling GAMIT
Two main files may need to be changed depending on data being processed
sestbl.
sets parameters for the sessions being processed
sittbl.
sets parameters for individual sites and defaults for sites
Both files reside in the tables directory
Links in day directories point to them.
“Standard example” versions of these files are for regional, bias fixed solutions.
28-Dec-18
GAMIT/GLOBK Tutorial 2

25. Apriori station coordinates
Estimating them is a multi-step process
generated from GLOBK (.apr) format apriori file with positions and velocities for each day
GAMIT reads L-file with geocentric spherical lat/long/radius but no time dependence
Apriori coordinates need to be good (discussed Lecture 3)
28-Dec-18
GAMIT/GLOBK Tutorial 2

26. Summary
The sh_gamit script provides a robust method for processing GPS data automatically and autonomously
Initial setup sometimes has problems, but once the first day of data runs without an error, the remaining days usually follow easily
28-Dec-18
GAMIT/GLOBK Tutorial 2