FGS Software Tools

The following FGS tools are written in standard Fortran and/or C and operate in the UNIX environment. A significant amount of this software was provided to STScI by the Space Telescope Astrometry Science Team (STAT) at the University of Texas and Lowell Observatory. However, please note that many of the tools produce graphical displays by calls to the SM¹ library, for which you may require a site license. STScI is working to replace the SM with a publicly licensed package. Until this is accomplished, if you need to use a non-SM graphics package, modest alterations to the source code will be necessary. Check the STScI FGS web pages for updates.

fgsplot	Tool to display a variety of FGS quantities (the location of the FGS Instantaneous Field of View in time as a function of x or y, the fine error signal, the photon counts v. time, etc.). Requires the raw GEIS files as input. Essential for analyzing failed observations and for retrieving useful information from marginal observations.
read-fgs	Reads the FGS GEIS header and data files and displays the contents of any of the seven groups of data contained in each data file.
export-fgs	Used to generate ASCII output of the six FGS GEIS header and data file combinations produced for each observation. Useful for non-standard processing and analysis.
gaussfit	Used primarily in the analysis and reduction of multi-epoch astrometry data, though is applicable to a wide variety of analysis topics - anything requiring robust, least-squares, or other types of estimation.
plot-rss	Tool for displaying the residuals of an astrometric catalog generated using gaussfit on CALFGSB output files.
ptrans	Tool for processing CALFGSA output of Transfer Mode scans.
binary-fit	Tool to model and compare Transfer Mode scans of an unresolved point source with scans of an observed (possibly binary) science target. binary-fit attempts to find a least squares solution to fit the observed S-curve morphology with a superposition of calibration S-curves.