vircam_dark_current
[Recipes]

Name:

vircam_dark_current

Purpose:

Calculate the dark current using a series of dark exposures.

Description:

An input series dark exposures with a range of exposure times is given. A linear fit is done at each pixel position of data number versus exposure time. A each pixel position in the output map represents the slope of the fit done at that position and is thus the dark current expressed in units of data numbers per second.

Language:

C

Parameters:

• thr (float): The rejection threshold in numbers of sigmas.
• ext (int): The image extension of the input files to be done on this run. If all of the extensions are to be processed, then this should be set to zero.

Input File Types:

The following list gives the file types that can appear in the SOF file. The word in bold is the DO category value.

• DARK_DARKCURRENT (required): A list of raw dark images with a range of different exposure times.
• MASTER_BPM or MASTER_CONF (optional): A master bad pixel mask or a master confidence mask. If this is not defined then all pixels are assumed to be good during the stats phase.

Output Products:

The following list gives the output data products that are generated by this recipe. The word in bold gives the PRO CATG keyword value for each product:

• The output dark current map (MASTER_DARK_CURRENT)

Output QC Parameters:

• DARKCURRENT The median dark current in data numbers per second found from the median value of the output dark current map.

Notes

None

Fatal Error Conditions:

• NULL input frameset
• Input frameset headers incorrect meaning that RAW and CALIB frame can't be distinguished
• Not enough dark frames in the input frameset
• Missing exposure times in file headers
• Unable to save data products

Non-Fatal Error Conditions:

• No master bad pixel or confidence map. All pixels considered to be good.

Conditions Leading To Dummy Products:

• Dark frame image extensions wouldn't load.
• The detector for the current image extension is flagged dead

Author:

Jim Lewis, CASU

Code Reference:

vircam_dark_current.c

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