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Most users of MIPS will use the dither pattern inherent to each AOT. Each
AOT has a slightly different dither pattern; descriptions of the dither
patterns are in the Spitzer Observer's
Manual (SOM), in the sections describing the motion of the telescope
and scan mirror for each mode. In SOM v. 5.0, section 8.2.1.1 (p. 275)
starts the discussion of scan map, and section 8.2.1.2 (p. 280) starts the
discussion of photometry. For most modes, there are tables of specific
source positions for the dither sequence. As an observer, you pick the
number of times to repeat this basic sequence.
If you really must have your own customized dither pattern, you may
accomplish nearly any pixel spacing by using one of two (or both) of the
following options. (1) The "raster map" option in
photometry. The basic dither pattern sequence is repeated at each
location in the raster map. Select the raster map option from within the
photometry AOT. (2) Cluster-mode targets. The basic
dither pattern sequence is repeated at each location given in the cluster
of targets, which can be specified in absolute, instrument, or offset
coordinates. Create cluster targets in the target window in Spot.
Always visualize your observation in Spot to be sure you really are
doing what you think you are doing!
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