Description Parameter: Section 4.5.1 Processing Level: SPD Usage in processing: File Type: FITS Image Units: dimensionless File Names: PP1VIGN, PP2VIGN, PP3VIGN, PC1VIGN, PC2VIGN
The light deflected by the chopper mirror can be vignetted. Since the chopper deflection can only take place along the spacecraft Y direction, the corrections are tabulated as a function of Y offset, detector, filter, and aperture, if any. The correction factors are multiplied with the mean and median signal per chopper plateau for a given chopper throw.
The vignetting Cal-G files contain no corrections for detectors P1, P2, and P3, i.e. all correction factors are unity for these detectors.
The present corrections for signal losses in pointed chopped observations implicitly include the chopper vignetting correction in the form of a different signal correction for the on- and off-target positions. Consequently, these observations require no additional vignetting corrections. The chopper vignetting corrections are used in the processing of PHT32 where no corrections for chopped signal losses are included.
All products have:
NAXIS = 3
TYPE = R*4
AXIS Length Description 1 14 Apertures:position, see Section A.1 2 25 Chopper position: from
to
in 15 arcsec steps 3 10 Filters:
position, see Section A.1
AXIS Length Description 1 14 Apertures:m
see Product PP2VIGN, with filters: 60 and 100 m.
AXIS Length Description 1 9 C100 Pixels: index 1= pixel [1,1], 2= [1,2], etc 2 25 Chopper position: from, see Section A.1
AXIS Length Description 1 4 C200 Pixels: pixel 1= [1,1], 2= [1,2], etc 2 25 Chopper position: from, see Section A.1