4.1 Analysis Tools
Not all of the tools described in the following sections will be required to analyze all FGS observations. Some of the tools (like binary-fit) are specific to the analysis of Transfer Mode observations, while tools like fgsplot are usable to analyze both Position Mode and Transfer Mode observations.
The following list should serve as a general guide to understanding the processes involved in FGS data analysis which tool to use in a given situation. As always, check the STScI FGS Website for updates.
- fgsplot
-Used 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 a input. Essential for analyzing failed observations and for retrieving useful information from marginal observations.
-FORTRAN and C modules. Runs in a UNIX and UNIX-based environments.
-Useful for Position Mode and Transfer Mode 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.
-FORTRAN and C modules. Runs in a UNIX and UNIX-based environments.
-Useful for Position Mode and Transfer Mode observations.
- export-fgs
-Used to generate ASCII output of the six FGS GEIS header anddata file combinations produced for each observation. Useful for non-standard processing and analysis.
-FORTRAN and C modules. Runs in a UNIX and UNIX-based environments.
-Useful for Position Mode and Transfer Mode observations.
- 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.
-Primarily C modules. Currently only runs under SUN Solaris and SunOS environments.
-Primarily used for Position Mode plate overlays, but is also applicable to Transfer Mode and Mixed Mode observations.
- plot-rss
-Tool to display the residuals of an astrometric catalog generated using gaussfit on CALFGSB output files.
-FORTRAN and C modules. Runs in a UNIX and UNIX-based environments.
-Useful for Transfer Mode observations only.
- ptrans
-Tool for processing CALFGSA output of Transfer Mode scans.
-FORTRAN and C modules. Runs in a UNIX and UNIX-based environments.
-Useful for Transfer Mode observations only.
- binary-fit
-Used 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.
-FORTRAN and C modules. Runs in a UNIX and UNIX-based environments.
-Useful Transfer Mode observations only.