3.3.6. globk.cmd
There are two required control files for sh_glred.
The names globk.cmd, and glorg.cmd are set by the script but can be overridden with the command line options -globk_cmd and -glorg_cmd.
Unlike the GAMIT sestbl. and sittbl., which for which entries must begin in column 1, all GLOBK files, as well as the sh_gamit control files process.defaults and sites.defaults, follow the convention that a non-blank first column denotes a comment (* or # below in the examples below) except that you can specify (arbitrary) keywords beginning in line 1 that match the <OPTIONS> list at the end of the globk/glred command line.
If the keyword is given as an option, globk/glred will replace the keyword in the command file by a blank, thus activating the command.
For example, with the command file shown below
$ sh_glred -expt emed -s 2018 34 2018 36 -ncomb 3 -globk_prefix COMB -opt G
will transform the command file from one appropriate for time series (solution for each day) one that will stack all of the days together and create a combined h-file for the period of the survey.
* globk command file for time series, short-term combinations and velocity solutions
* Set COMB as a globk command line option for short-term combinations; since these commands
* follow the commands for repeatabilities, they will take precedence when invoked.
* Set VEL as a globk command-line option for velocity; since these commands follow
* the commands for repeatabilities, they will take precedence when invoked.
* Set KEEP to allow glorg to be run separately after run; useful for testing
* as a globk command-line option.
* Any combination, e.g. COMB+KEEP or VEL+KEEP will use both (or more) options.
* Lasted edited 180705
* << column 1 must be blank if not comment >>
* Use wild-cards in file names so that parallel runs do not overwrite
* each other. The "@" symbol is replaced with the .gdl-file name root.
* This group of commands must appear before any others:
eq_file ~/gg/tables/igb14_comb.eq
ITRF08 eq_file ~/gg/tables/itrf08_comb.eq
# Optionally add a second eq_file for analysis-specific renames
x eq_file my_eq_file.eq
# For time-series glred runs, it's faster not to use the "com_file" command
# (com_file need not be created; only needed if glorg or glsave are to be
# run by themselves after globk completes).
* This group of commands must appear before any others:
KEEP com_file @.com ! Allows parallel runs, provide h-file list name is different
srt_file @.srt
srt_dir +1
# Normally for combined files, make_svs is not needed. Only needed if
# orbits are to be estimated.
x make_svs @.svs A
* End of commands that must appear first
* Solution file pointed to by the com file, if used
VEL sol_file @.sol
The first group of commands define files used by glred/globk and which must be listed first in the command file in order for the program to work properly.
For time series computations, all but the eq_file can be considered scratch files.
The eq_file, described below, allows you to exclude sites or to rename them to account for breaks due to earthquakes or instrument changes.
* ITRF augmented by now-defunct sites and recent IGS solutions;
* matched to igb14_comb.eq (ITRF2014; default) or itrf08_comb.eq ("ITRF08" command-line option)
apr_file ~/gg/tables/igb14_comb.apr
ITRF08 apr_file ~/gg/tables/itrf08_comb.apr
# Optionally add additional apr files for other sites
# Do not used an a priori rotation file with multi-day H-files
x in_pmu ~/gg/tables/pmu.usno
* Correct the pole tide when not compatible with GAMIT.
* Use caution here is binary hfiles from SINEX are used since these
* file do not contain status of pole tide correction.
app_ptid all
The next two entries specify the a priori files to be used for Earth orientation and coordinates. If these are omitted, the values will be taken from the h-file (i.e., the GAMIT solution), which may be fine in many circumstances.
* Set maximum chi2, prefit coordinate difference (m), and rotation (mas) for an h-file to be used;
max_chii 13 3 100
# increase tolerances to include all files for diagnostics
x max_chi 100 5.0 20000
The max_chi command allows automatic removal of an h-file when the data are bad, detected in globk by checking for a high \(\chi^2\), a large adjustment of coordinates from their a priori values, or a large rotation of the network.
For a network less than 10 km in extent, it may be necessary to loosen these values since the rotation will not be well determined.
* Invoke glorg
org_cmd glorg.cmd
* Print file options
crt_opt NOPR
prt_opt NOPR GDLF
org_opt PSUM GDLF FIXA RNRP
COMB org_opt ERAS PSUM CMDS GDLF FIXA RNRP
VEL org_opt ERAS PSUM CMDS GDLF VSUM FIXA RNRP
# The output .org-file will be generated from the
# .prt-file name from the globk command line
# sh_glred will name the glorg print files
# To set an explicit name for the glorg print file
# globk print file name from the globk command line
x org_out glred_------.org
xCOMB org_out globk_------.org
xVEL org_out globk_------.org
Including the name of the glorg command file (org_cmd glorg.cmd) tells globk to call glorg for frame definition (“stabilization”) after globk is run.
The org_opt command prescribes what is included in the glorg print summary (.org file).
PSUM means a summary of position adjustments;
GDLF means to list the name of the input h-file;
and CMDS means to echo both the globk and glorg command files.
If you are invoking glorg, then the globk print will not be very useful and is suppressed by prt_opt NOPR.
* Coordinate parameters to be estimated and a priori constraints
apr_site all 10 10 10 0 0 0
VEL apr_site all 10 10 10 1 1 1
* Rotation parameters to be estimated and a priori constraints
apr_wob 10 10 1 1
apr_ut1 10 1
# EOP tight if translation-only stabilization in glorg (also comment out mar_wob, mar_ut1)
x apr_wob .25 .25 .1 .1
x apr ut1 .25 .1
* For multiday combinations allow EOP's to change between days.
* The rate terms here depend on nature of gamit solutions:
* For RELAX. solutions, EOP rates are estimated and when combined
* with daily MIT .GLX-files, the rates are allowed to change and
* will be jointly estimated between the MIT and local file. When
* baseline processing is used, the rates would only apply to MIT
* files.
COMB mar_wob 3650 3650 365 365
COMB mar_ut1 365 365
VEL mar_wob 3650 3650 0 0
VEL mar_ut1 365 0
* Allow rotation when using SINEX files that do not contain EOP parameters
x apr_rot 10 10 10 1 1 1
x apr_rot .25 .25 .25 .1 .1 .1
xCOMB mar_rot 3650 3650 365 365 365 365 0 0 0
xVEL mar_rot 3650 3650 365 0 0 0 0 0 0
* Translation a priori constraints
apr_tran 1 1 1 0 0 0
xVEL apr_tran 1 1 1 1 1 1
xVEL mar_tran 3.65 3.65 3.65 0 0 0
# Allow scale variations for pre-1995 data and for data analyses that feature a change
# in SV PCVs (e.g. operational, pre-repro1 MIT or SOPAC h-files before Week 1400, Nov 2006)
SCALE apr_scale 10 0
xVEL apr_scale 10 1.
xVEL mar_scale 365 0
* If orbits free in GAMIT (RELAX.) and you want them fixed, use:
x apr_svs all F F F F F F FR
* but if you are combining with globk h-files, better to leave them
* on but, if the models are incompatible, turn off radiation-pressure parameters,
x apr_svs all 100 100 100 10 10 10 0R
* When using MIT GLX files, which have satellite phase center positions
* estimated, fix antenna offsets to IGS a priori values by using:
apr_svan all F F F
* When combining multiple h-files from the same epoch,
* estimate atmospheric zenith delay at common sites
apr_atm common 1
COMB mar_atm common 3.65
VEL mar_atm common 3.65
Commands of the form apr_ serve both to tell globk to estimate the parameter and to specify the a priori constraint to be used.
If you are stabilizing by estimating both translation and rotation in glorg (the usual case with a robust network), then both the coordinate (apr_neu) and EOP (apr_ut1 and apr_wob) constraints should be loose, as shown above.
If you estimate only translation in glorg, preferable for less than four stations or a network less than 1000 km in extent, then you should tightly constrain EOP (and orbits).
To apply finite constraints instead (not recommended), set the apr_neu values as appropriate for each station and do not invoke glorg (comment out the org_cmd line).
x apr ut1 .25 .1
* For multiday combinations allow EOP's to change between days.
* The rate terms here depend on nature of gamit solutions:
* For RELAX. solutions, EOP rates are estimated and when combined
* with daily MIT .GLX-files, the rates are allowed to change and
* will be jointly estimated between the MIT and local file. When
* baseline processing is used, the rates would only apply to MIT
* files.
COMB mar_wob 3650 3650 365 365
COMB mar_ut1 365 365
VEL mar_wob 3650 3650 0 0
VEL mar_ut1 365 0
* Allow rotation when using SINEX files that do not contain EOP parameters
x apr_rot 10 10 10 1 1 1
x apr_rot .25 .25 .25 .1 .1 .1
xCOMB mar_rot 3650 3650 365 365 365 365 0 0 0
xVEL mar_rot 3650 3650 365 0 0 0 0 0 0
* Translation a priori constraints
apr_tran 1 1 1 0 0 0
xVEL apr_tran 1 1 1 1 1 1
xVEL mar_tran 3.65 3.65 3.65 0 0 0
# Allow scale variations for pre-1995 data and for data analyses that feature a change
# in SV PCVs (e.g. operational, pre-repro1 MIT or SOPAC h-files before Week 1400, Nov 2006)
SCALE apr_scale 10 0
xVEL apr_scale 10 1.
xVEL mar_scale 365 0
* If orbits free in GAMIT (RELAX.) and you want them fixed, use:
x apr_svs all F F F F F F FR
* but if you are combining with globk h-files, better to leave them
* on but, if the models are incompatible, turn off radiation-pressure parameters,
x apr_svs all 100 100 100 10 10 10 0R
* When using MIT GLX files, which have satellite phase center positions
* estimated, fix antenna offsets to IGS a priori values by using:
apr_svan all F F F
* When combining multiple h-files from the same epoch,
* estimate atmospheric zenith delay at common sites
apr_atm common 1
COMB mar_atm common 3.65
VEL mar_atm common 3.65
Sites to include in the solution are selected or deselected with use_site.
The default is to include all sites in the h-file(s), but you can command a subset by started the list with clear followed by the site names, either four characters (all 8-character versions of the site) or the full eight (to select only certain versions);
listing the site preceeded by a minus will remove it from the list.
In the example we’ve referred to a separate file (../tables/uselist) rather than include the use_site commands in the main command file.
For site selection from an h-file of global processing, you can invoke the use_pos to include or exclude sites within a geographical region.
(See the globk help file or Section 3.1 of the GLOBK Reference Manual.)
* Write out a combined H-file
# Can substitute your analysis name for 'COMB' in the file name below
COMB out_glb H------_COMB.GLX
VEL out_glb @.GLX
* Remove scratch files for repeatability and combination runs
del_scra yes
KEEP del_scra no
The out_glb command, when invoked, tells globk to write the solution out in the form of an h-file.
This is useful for aggregating data in weekly or monthly averages and/or combining your own processing with global or regional h-files from an external source (see Chapter 4).
* Turn off quake log estimates if in the eq_file
free_log -1
If you need to provide for step changes in coordinates (or velocities) and/or to exclude sites during certain periods, you can use an “earthquake-rename” file (eq_file) with globk.
The file has two types of entries.
The first renames sites (creates new logical sites for globk) automatically based on their proximity to an earthquake:
# November 3, 2002, UT=22:12 Lat = 63.52 Lon -147.53 Depth=5 km M 7.9
eq_def DN 63.52 -147.53 700 5. 2002 11 3 22 12
eq_cosei DN 1.0 1.0 1.0 1.8 1.8 0.7
eq_post DN 100 0.1 0.1 0.1 1.8 1.8 0.7 Postseismic: 0.1 mm**2/day
eq_rename DN
With the lines above included in the eq_file, all sites within 700 km of the 2002 Denali (Alaska) earthquake will be renamed (_gps to _gdn) for h-files with start and stop times later than 22:12 on 3 November 2002.
The eq_cosei and eq_post commands prescribe the constraints applied to the co-seismic and post-seismic changes.
(See the globk help file and Section 3.1 of the GLOBK Reference Manual.)
The second type of command renames sites according to explicit instructions to account for changes in data quality or instrumentation:
rename mate_gps mate_1ps 1999 6 18 0 0
rename kit3_gps kit3_xcl 1997 5 14 0 0 1997 5 18 0 0
rename madr_gps madr_xhi emed 1996 9 26 0 0 1996 10 27 0 0
The first of these lines accounts for a position change with the introduction of a new receiver at Matera;
the second removes some bad data at Kitab for a four-day period;
the third accounts for the use of an incorrect antenna height in h-files whose names include the substring emed.
You may use the equate feature of glorg to force the horizontal adjustments for madr_gps and madr_xhi to be the same (see Chapter 4).
It is also possible to use the rename command to shift the position of a site without introducing a new site, useful to apply offsets known from local measurements or assumed from an earthquake model:
rename tigr_gni tigr_gni 2001 2 28 0 0 2100 1 1 0 0 0.0032 0.0033 0.0000 NEU
The entry applies 3 mm offsets of the north and east coordinates of the site based on an a priori model for the Nisqually (NI) earthquake near Seattle, Washington.
For ITRF sites the igb14_comb.eq file provides a set of renames consistent with the igb14_comb.apr file (similarly itrf08_comb.eq and itrf08_comb.apr).