STScI Logo
STScI Logo
HST
Banner
FAQ

Q: What photometric information is available from the guiding FGSs regarding the photometry of the Guide Stars?

A: Star Selector encoder readings and photomultiplier tube counts are available for Guide Stars at a 40 Hz rate for all astrometry observations.

For non-astrometry observations taken after early 1995, 40 Hz Guide Star data is available; for observations made earlier, thtelemetryry format and frequency of the Guide Star data were generally determined by the science instrument, with frequencies ranging from 40 Hz to 0.667 Hz.
Shortcuts

FGS Instrument Handbook
FGS Data Handbook


Copyright  | Help  | Printable Page