As a scientific instrument, the FGSs are capable of providing photometric measurements of point sources. The basic photometric capabilities of the FGS are:
- 40Hz 1-2% long-term relative photometry.
- 40Hz milli-magnitude relative photometry over orbital timescales.
The absolute FGS photometric response of FGS3 has been stable at the 2% level over the past eight years (L. Reed, BF Goodrich) . FGS1r is expected to be as stable or better. For relative photometry on time scales of orbits, the FGS has been shown to be stable at the 1 milli-magnitude level, thus affording an opportunity for 0.1-0.2% time series photometry.
For more specific details on FGS photometry, follow the links to the documents listed below.
FGS Photometry Documentation:
See Section 3.6 of the FGS Instrument Handbook
Instrument Science Reports:
ISRs are technical reports written by members of the FGS Group about various aspects of the instrument and data. They usually contain in-depth information about specific topics.
Addendum: Results From FGS Cycle 5 Calibration Programs #6180 and #6181
Results of the observation of the blue target LAT-COL-1B from Cycle 5 FGS calibration
programs #6180, Red/Blue Transfer Function Calibration for the Clear (F583W), and
PUPIL filters are discussed.
Results From FGS Cycle 5 Calibration Programs #6180 and #6181
Results from Cycle 5 FGS calibration programs #6180 and #6181, Red/Blue Transfer
Function Calibration for the Clear (F583W), PUPIL, and Neutral Density (F5ND) filters
are discussed.
Results From FGS Cycle 5 Calibration Program #6175 3 Points of Light
Results from the Cycle 5 FGS calibration program #6175, 3 Points of Light , are discussed.
Correcting FGS Counts for Deadtime in the PMTs
The procedure to remove the effect of deadtime is described in-depth.
Papers and Proceedings:
Selected FGS related published papers and workshop proceedings.