DARK_AND

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DARK_AND_BPM

Measures dark current and creates a new bad-pixel mask for UIST

Description:

This recipe is used to measure the dark current for UIST, using a long-exposure DARK frame. It first finds and bad pixels in the DARK, then measures and reports the dark current. The recipe appends to a tabulation of the dark current in an engineering log file, $ORAC_DATA_OUT/uist_array_tests.log, which it creates with headings if the log does not exist.

Notes:

The recipe applies thresholds to the dark frame and flags pixels outside these limits as bad. The thresholds are derived from 3-standard-deviation clipped statistics; pixels more than 5 standard deviations above the mean are flagged.
The bad pixels detected are added into the current bad-pixel mask and then this is filed with the calibration system as a new and current bad-pixel mask.
The new bad-pixel mask is applied to the original dark frame, whose unclipped mean scaled by the gain and inverse exposure time is the dark current in electrons per second.

Output Data

The engineering log $ORAC_DATA_OUT/uist_array_tests.log.

Related Recipes

ARRAY_TESTS, MEASURE_READNOISE.

Implementation Status:

The processing engines are from the Starlink package Kappa.
Uses the Starlink NDF format.
History is recorded within the data files.
Error propagation is not used.

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