Reduces an imaging flat field REDUCE_FLAT
This recipe will reduce any image passed to it. Care must be taken to ensure that a proper flat-field image will be reduced.
The bad pixel mask applied is $ORAC_DATA_CAL/bpm.
The flat field is normalised using a clipped mean, where the clipping levels are 2, 3, and 3 standard deviationss. This value is effectively the mode of the image. The entire image is divided by this value to normalise it.
Intermediate frames are deleted.
The flat is called flat_frame_number
.
The flat is filed in $ORAC_DATA_OUT/index.flat.