Dark subtraction for older West-12/East-14/DRACO images

Orginially by default we originally only stored the raw images in the archive, i.e. not the dark frame subtracted images and hence older images may require additional processing.

photom_ad.py

The automatic reduction pipeline ("photom_ad.py") automatically subtracts a dark frame when one is provided in the processing directory.

Current Images

Now as well as the raw images (i.e. 0***.fits), dark frame subtracted images are also provided in the archive ( i.e. d0***.fits).

DRACO

Currently only the raw CCD images taken with DRACO are stored in the archive and dark subtracted images must be produced. First copy a recent dark frame taken at the same temperture and exposure time as your image to your workspace, e.g.


 \cp -p /draco/2005/darks/2005_02_03_master_dark_2.sdf master_dark.sdf

Initialise the Starlink kappa package, e.g.

 kappa

Now subtract the dark frame, e.g.


 sub 0171.fits master_dark s_0171

This will create the file:

 s_0171.sdf

which can be displayed with Gaia.

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jrl

2020-Jun-17 13:42:35 UTC