14.15 Inhomogeneous FCS illumination of PHT-P


Description Parameter:	 Section 4.5.4
Processing Level:	 SPD
Usage in processing:	 Section 7.10.3
File Type:		 FITS Image
Units:			 dimensionless
File Names:		 PP1FCSAP, PP2FCSAP, PP3FCSAP,

As already implemented for PHT-C (FCS illumination matrices `PC1ILLUM' in Section 14.14.1 and `PC2ILLUM' in Section 14.14.2), the PHT-P calibration must also be corrected for inhomogenous FCS illumination. This implies that the power on the detector from the FCS does not scale directly with the aperture area (which whould be the case for a perfectly homogeneous illumination) but that an additional correction factor is necessary.

For all aperture correction Cal-G files the following FITS keywords are common:
NAXIS = 4
TYPE = REAL*4

14.15.1 Product PP1FCSAP: FCS aperture correction tables for P1


AXIS	Length	Description
1	14	apertures: CHWII position (see Section A.1)
2	10	filters: CHWIII position (see Section A.1)
3	2	Each FCS
4	2	Correction and uncertainty

14.15.2 Product PP2FCSAP: FCS aperture correction tables for P2


AXIS	Length	Description
1	14	apertures: CHWII position (see Section A.1)
2	2	filters: 20, 25 m
3	2	Each FCS
4	2	Correction and uncertainty

14.15.3 Product PP3FCSAP: FCS aperture correction tables for P3


AXIS	Length	Description
1	14	Apertures: CHWII position (see Section A.1)
2	2	Filters: 60, 100 m
3	2	Each FCS
4	2	Correction and uncertainty

Next: 14.16 PHT-P Filter-to-Filter Corrections Up: 14. Calibration-G Products Previous: 14.14 Array Illumination by

ISO Handbook Volume IV (PHT), Version 2.0.1, SAI/1999-069/Dc