Calibration Access and Data Handbook

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The dark frame map contains all non-uniformities across the CCD surface. It will be shifted additively by CAL_offsetCorrect with the offset available either from CCF ADUConv or as the output of rgsoffsetcalc.

The dark frame will be stored in parameterized form in CCF DarkFrame on a per node basis. The functional form is

f = a_0\times e^{a_1 {\tt (rawX-1)}} + a_2\times {\tt (rawX...
b_0\times e^{b_1 {\tt (rawY-1)}} + b_2\times {\tt (rawY-1)} \end{displaymath}

with parameters $a_0$ to $a_3$ and $b_0$ to $b_3$ that are available from CCF DarkFrame.1

Modifications of the dark frame due to light leaks from imperfections of the Al-filter will be included.

This routine is mainly used by CAL_gainCorrect to obtain the local offset at the position rawX & rawY.

Michael Smith 2011-09-20