Occasionally "scuffs" are apparent in reduced SCUBA-2 images. These scuffs are a result of one or more sub-arrays entering into a higher noise state for a period of time.
It is possible to down-weight data that have higher noise by setting NOI.BOX_SIZE in your configuration file. The length of time over which the noise is analyzed can either be specified in time samples (positive values) or seconds (negative values).
It has been found setting NOI.BOX_SIZE=-15 (i.e. half a sub-scan) is a good value to use. As this value tends to -1 (one second) we find some of the source signal being down weighted. Higher than this -15 value and the map-maker becomes less sensitive to the higher noise states.
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| Left: reduction without NOI.BOX_SIZE specified. Right: reduction with NOI.BOX_SIZE=-15 specified in the config file. |
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| The difference map: we see these scuffs are removed from the final image. |
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