Chapter 3:
Calibration
3.1 Preparing FGS Data for Processing
3.2 Initial Data Processing - calfgsa
3.2.1 calfgsa and Transfer Mode Data
3.2.2 calfgsa and Position Mode
3.3 calfgsa Processing Overview
3.4 calfgsb and Position Mode
3.4.1 preparing to use calfgsb
3.4.2 executing calfgsb
3.5 Position Mode Processing Overview
3.5.1 Processing Individual Observations
3.5.2 Visit level processing
3.6 calfgsa Output: The *.tab File
This chapter describes the routine reduction and calibration of raw FGS data. Unlike data from other HST instruments, data from the FGS are not calibrated by an automated pipeline process. This task is left to the user.
To facilitate FGS data calibration, STScI provides two IRAF/STSDAS tasks - calfgsa and calfgsb - which enable observers to calibrate their data using the current best set of reference files and algorithms. This chapter describes these tasks in detail, and should serve as a guide for when to use calfgsa or calfgsb on FGS data.
