ORAC-DR records calibration information, such as dark frames, flat fields, and the read noise, within index files, one for each type of calibration information. When the pipeline needs a calibration frame it searches the index file for the best matching entry subject to a set of rules. Each recipe reports the calibrations it has used. If no suitable calibration exists, the pipeline exits with an error message stating this fact. For further details see SUN/230. Here is an example index file. You can also select a specific calibration using the -calib command-line option, provided the chosen calibration has an entry in the appropriate index file. See calibration options for details and examples.
ORAC-DR -- imaging data reduction