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Next: 13.9 Correction for signal Up: 13 Calibration G Products Previous: 13.7 Detector dark signals

Subsections

13.8 Vignetting Corrections   


Description Parameter:	 section 4.5.1
Processing Level:	 SPD 
Usage in processing:	 section 7.3.8
File Type:		 FITS Image 
Units:		 	 dimensionless
File Names:		 PP1VIGN, PP2VIGN, PP3VIGN,
		 	 PC1VIGN, PC2VIGN
The light deflected by the chopper mirror can be vignetted and possible vignetting corrections should be applied. 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 related to OLP Version 7 contain no corrections for detectors P1, P2, and P3, i.e. all correction factors are unity for these detectors.


All products have:
NAXIS = 3
TYPE = R*4

13.8.1 Product PP1VIGN: vignetting corrections for P1   


AXIS		Length		Description
1		14		Apertures: $\rm CHWII$ position, see section A.1)
2		25		Chopper position: from -180'' to +180'' in 15 arcsec steps
3		10		Filters: $\rm CHWIII$ position, see section A.1)

13.8.2 Product PP2VIGN: vignetting corrections for P2   


AXIS		Length		Description
1		14		Apertures: $\rm CHWII$ position, see section A.1)
2		25		Chopper position: from -180'' to +180'' in 15 arcsec steps
3		2		Filters: 20, 25 ${\mu}$m

13.8.3 Product PP3VIGN: vignetting corrections for P3  

see Product PP2VIGN, with filters: 60 and 100 ${\mu}$m.

13.8.4 Product PC1VIGN: vignetting corrections for C100   


AXIS		Length		Description
1		9		C100 Pixels: index 1= pixel [1,1], 2= [1,2], etc
2		25		Chopper position: from -180'' to +180'' in 15 arcsec steps
3		7		Filters: $\rm [CHWII~position-1]$, see section A.1

13.8.5 Product PC2VIGN: vignetting corrections for C200   


AXIS		Length		Description
1		4		C200 Pixels: pixel 1= [1,1], 2= [1,2], etc
2		25		Chopper position: from -180'' to +180'' in 15 arcsec steps
3		5		Filters: $\rm CHWII-8$ position, see section A.1
next up previous contents
Next: 13.9 Correction for signal Up: 13 Calibration G Products Previous: 13.7 Detector dark signals

ISOPHOT Data Users Manual, Version 4.1, SAI/95-220/Dc