Calibration Strategy
From the Observer’s viewpoint, absolute flux calibration will be tied to the frequent stimulator flashes and to periodic observations of well-calibrated celestial standards.
The general strategy as it is currently planned includes:
- The fundamental MIPS flux calibration will be against normal stars.
- Atmospheric models will be used to extrapolate the well determined calibration at 10 ?m into the far infrared.
- MIPS calibrator stars will be observed at the start and end of instrument campaigns.
- The stimulators will be used as relative calibrators, to allow the instrument response to be referred to the signals from the celestial standards without actually observing them. For the Ge:Ga arrays the stimulators will be flashed approximately every 2 minutes. The Si array will need infrequent stimulator calibrations.
- Flat fielding
- The stimulator and internal flat field projector illumination patterns to be calibrated by uniform sky.
- Annealing the arrays
- Ionization damage will need to be removed from the MIPS germanium focal planes roughly every three hours. Three methods are available: thermal anneal, bias boost, and photon flood. The Si:As focal plane will be annealed about once per week.