Description Parameter: Section 4.2.7 Processing Level: SPD Usage in processing: Section 7.10.4 File Type: FITS Image Units: Dimensionless File Names: PC1FLAT, PC2FLAT
The responsivity of the individual detector pixels in the C100 and the C200 arrays vary from one filter to the other. These variations are different for different pixels in the array. Consequently, the flat-field of the array differs from one filter to the other. The flat-field is in principle calibrated out by the FCS measurement, but for multi-filter measurements where only 1 FCS measurement is taken, the flat-field correction must be applied when determining the fluxes in the filters in which the FCS was not taken.
For both detector flat-field calibration files the following FITS keywords
are common:
NAXIS = 3
TYPE = REAL*4
AXIS Length Description 1 9 C100 pixels, in same order as SPD. 2 7 filters:(see Section A.1) 3 2 Correction and uncertainty
AXIS Length Description 1 4 C200 pixels in the same order as in SPD 2 5 Filters:(see Section A.1) 3 2 Correction and uncertainty