THE ISOCAM STANDARD DATA REDUCTION

Recommendations, Hints, Guide-Lines and Pitfalls

CO-ADDING IMAGES

By default the CIA procedure reduce computes a straight mean frame (while ignoring glitched or other ``bad'' pixels) for a given ISO pointing (or observing mode). Other options are to produce a median combined frame or a weighted mean by using the errors. If the data are not properly stabilized either the mean or the median option will result in under-estimating the signal. It may be necessary to customize this step. For example, by computing a weighted mean where the weights are computed from the degree of stabilization in the raw data cube.

Recommended reading:

• Section 20.2.4 of the CIA manual (version 4.0).

Expected time commitment:

• Few seconds to few minutes depending on the number of fields observed.

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