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A description of how the data is dithered (or jittered)
It is common practice to split a long NIR exposure into several short exposures at slightly different positions in order to minimize the contribution from bad pixels and cosmic rays and to avoid background saturation. Dithering shifts and combines these input frames into a single output using the appropriate dither offsets.

These dither offsets are initially calculated from the WCS parameters in the FITS headers that have been generated from the astrometric calibration. The offsets are then further refined by object position cross-correlation.

Note that the offsets are always whole pixels so no resampling is required.