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Micro-scan

 

We consider a micro-scan lasting , consisting of exposures on different pointings ( = for a raster scan of M points along N lines). Each exposure is obtained by averaging successive elementary images with integration time . Some area of the sky covered by the raster will be seen by different pixels:

where and are the displacements, in arc seconds, in each direction.

Assuming that an optimal micro-scan data reduction solution is obtained simultaneously for the sky image and detector response, in areas seen by different pixels, the rms uncertainty for a single position in the final map is obtained as follows:

By definition:

where:

 

and:

 

Solving equations gif and gif:

 

where :

is the HF term of the detector noise.

The LF noise is as given above, but with the appropriate observing times:



ISOCAM Observer's Manual - V1.0
Tue Oct 31 12:06:23 MET 1995