.. _intro_proc:

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Automatic Processing with GAMIT and GLOBK
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.. toctree::
   :hidden:

   setup/index
   flow
   control/index
   example

GAMIT is composed of distinct programs which perform the functions of preparing the data for processing (:program:`makexp` and :program:`makex`), generating reference orbit and rotation values for the satellites (:program:`arc`, :program:`yawtab`), interpolating time- and location-specific values of atmospheric and loading models (:program:`grdtab`), computing residual observations (\ ":math:`\text{o} - \text{c}`"s) and partial derivatives from a geometrical model (:program:`model`), detecting outliers or breaks in the data (:program:`autcln`), and performing a least squares analysis (:program:`solve`).
Although the modules can be run individually, they are tied together through the data flow, particularly file-naming conventions, in such a way that most processing is best done with shell scripts and a sequence of batch files set up by a driver module (:program:`fixdrv`) for modeling, editing, and estimation.
Though the data editing is almost always performed automatically, the solution residuals can be displayed or plotted so that problematic data can be identified (:program:`cview`).

Likewise, GLOBK operates through distinct programs, which can be invoked with a single command or run separately.
The primary functions are to combine quasi-observations—either GAMIT/GLOBK "h-files" or the internationally accepted SINEX format—from multiple networks and/or epochs (:program:`glred` or :program:`globk`), and to impose on this solution a reference frame appropriate to the scientific objective (:program:`glorg`).
Note that :program:`globk` and :program:`glred` are the same program, just called in different modes:
:program:`glred` to read data from one day at a time for generating time series;
:program:`globk` for stacking multiple epochs to obtain a mean position and/or velocity.

The full sequence of steps to take you from phase data to time series is accomplished with two shell scripts:

:program:`sh_gamit` looks for RINEX data over a range of days and invokes the GAMIT programs to produce constrained and loose estimates of coordinates together with sky plots of phase data as a record of the processing;

:program:`sh_glred` uses the GAMIT results to produce time series of day-to-day repeatability or a combined h-file that may be further combined with those from other epochs to estimate station velocities.

The only preparation required is assembling the meta-data from station logs;
setting up the control files, most of which are common to all analyses of a particular era;
and assembling RINEX files not available from public archive in one or more directories on your system.

Note that all of the scripts and programs that use command-line control are self-documenting:
to see the input commands, just type the script or program name with no arguments.