.. _test_gamit2018: Run GAMIT for three days in 2018 ================================ In the :file:`test_install/2018/` directory type .. code-block:: console $ sh_setup -yr 2018 .. dropdown:: What did this command do? :color: warning :icon: question You should notice that a :file:`tables/` sub-directory was created, which contains copies of several critical files, most generic but some specific to the year, from the main :file:`~/gg/tables/` directory. You may wish to edit some of these files to suit your needs to process your experiment. Take a look at what was generated, e.g. :console:`ls -l tables/`. The :file:`2018/tables/` directory will now contain links to most standard files in :file:`~/gg/tables/` and copies of these files for :file:`process.defaults`, :file:`sestbl.`, :file:`station.info` (complete MIT version), and :file:`autcln.cmd`. The :file:`sites.defaults` file was written for this test (ordinarily one would construct this station list) and already in the directory, and therefore not overwritten by :program:`sh_setup`. Examine :file:`tables/sites.defaults` to note that it has been set up to download from a remote archive (CDDIS by default) RINEX files for ten IGS stations and :content:`xstinfo` is set to avoid any automatic update of :file:`station.info` during processing. Note also that the :file:`sittbl.` copied from :file:`~/gg/tables/` is set up to impose moderate constraints on IGS core stations to support ambiguity resolution in GAMIT; the four included in test_install are more than sufficient. Edit :file:`tables/process.defaults` to change the :content:`mailto` to your own email address to receive the :program:`sh_gamit` summary file. (If left null, it reverts to :command:`whoami`, so this change may not be needed.) Note that :content:`aprf`, used to initialize the :file:`lfile.` for GAMIT points to :file:`igb14_comb.apr`, which has been copied by :program:`sh_setup` to the :file:`2018/tables/` directory. If you have not downloaded or copied from an earlier distribution the (large) grid file for ocean tidal loading and do not wish to use it, change :content:`Tides applied` in :file:`tables/sestbl.` from :content:`31` to :content:`23`. Construct a small, experiment-specific station.info file by using the following procedure in the :file:`2018/tables/` directory: .. code-block:: console $ sh_upd_stnfo -l sd will create :file:`station.info.new`, using from the MIT station.info only the sites listed in :file:`sites.defaults`. (This step will take a while since the MIT global :file:`station.info` file is so long.) After checking, rename it to :file:`station.info` (overwriting the no-longer-useful MIT :file:`station.info`). (In your own processing, if you have stations that are not in the MIT :file:`station.info` file, you can add their entries from the RINEX headers by running in :file:`tables/` .. code-block:: console $ sh_upd_stnfo -files ../rinex/*.18o (See :numref:`intro_proc_example` of :doc:`/intro/index` for what to do if the RINEX header entries are non-standard.) GAMIT currently supports processing of each GNSS separately, with the day directories for each created with a single-letter added to designate the system, e.g. :file:`095G/`, :file:`095R/`, :file:`095E/`, :file:`095C/`. If you wish to test full GNSS capability, type at the :file:`2018/` level .. code-block:: console $ sh_gamit -expt eura -gnss G -s 2018 095 097 -pres ELEV -orbit igsf -copt x k p -dopts c ao >& sh_gamit_2018G.log sh_gamit -expt eura -gnss R -s 2018 095 097 -jclock sp3 -pres ELEV -orbit codm -copt x k p -dopts c ao >& sh_gamit_2018R.log sh_gamit -expt eura -gnss E -s 2018 095 097 -pres ELEV -orbit codm -copt x k p -dopts c ao >& sh_gamit_2018E.log sh_gamit -expt eura -gnss C -lfreq 7 -s 2018 095 097 -pres ELEV -orbit codm -copt x k p -dopts c ao >& sh_gamit_2018C.log For GPS-only, execute only the first command and omit the :option:`-gnss` so that the day directory names will be the day-of-year only. A summary file should be emailed to you as each day completes execution. Check these files for number of stations (6), postfit RMS (3–15 mm, none 0), postfit NRMS (~ 0.2), ambiguity resolution and coordinate adjustments (< 30 cm). For this large network, the 2018 ambiguity resolution is 80–90% for GPS and Galileo, 40–50% for Beidou, but near zero for GLONASS due to poor orbits), a condition also reflected in the sky plots in the :file:`figs/` directory. Allowing the GLONASS orbits to adjust (:content:`RELAX` mode in the :file:`sestbl.`) will improve the fit signficantly. To view the result of the fit of GAMIT's orbit model to the input orbit, see the RMS files in :file:`igs/`. To view the complete editing statistics see :file:`autcln.prefit.sum` and :file:`autcln.post.sum` in the day directories; for the least-squares adjustment, see :file:`qeuraa.{}`. Optionally, remove the x, k, and p files from the day directories to save space: .. code-block:: console $ sh_cleanup -d 2018 095 096 097 -dopts x k p .. _test_gamit2018_notes: Notes: 1. For large or complex data sets, the utility :program:`sh_get_times` can be helpful in determining the days and session spans to be processed. 2. In creating :file:`station.info` for your own experiments, it is important to check it after updating from the RINEX headers unless you are sure these headers are correct. In processing, the :file:`station.info` entries always override whatever is in the RINEX header or the x-files. An alternative way of creating entries for survey-mode sites is to use interactive program :program:`make_stnfo`, then use :program:`sh_upd_stnfo` to merge this file with the one created from the MIT :file:`station.info` file for continuous sites. The survey-mode file will have a shorter form of the :file:`station.info` format, but this will be converted when it is merged with the continuous file, which should be listed as the reference (:option:`-ref`) in the call to :program:`sh_upd_stnfo`. 3. The example is set up to use ocean tidal loading (:content:`Use otl.grid = Y` in the :file:`sestbl.`), which requires you to have previously downloaded into :file:`~/gg/GRIDS/` an OTL file from ftp://everest.mit.edu/pub/GRIDS/ and to have verify this file is linked to :file:`~/gg/tables/otl.grid`. The IERS/IGS standard model is :download:`otl_FES2004.grid ` (730 Mb). You may, however, substitute the smaller (45 Mb) :download:`otl_CSR4.grid `, or you may turn off ocean tidal loading by setting :content:`Tides applied = 23` and :content:`Use otl.grid = N` in the :file:`sestbl.` (Note that the links to the other grid and list files (:file:`met.grid`, :file:`met.list`, :file:`map.grid`, etc.) can remain empty for running the example and for most processing. 4. If you want or need to run the example without having internet access while running, you can pre-load the RINEX, navigation, and orbit files into the :file:`rinex/`, :file:`brdc/`, and :file:`igs/` directories, respectively.