Running REDUCE/CCD

The command REDUCE/CCD can process one or more science frames automatically provided that:

• the association table correctly describes the associations between the science frames and the calibration frames;
• the CCD reduction table or the SC_... keywords contains the correct names of the master calibration frames;
• the keywords for creating the calibration frames are correctly set.

The standard default calibration procedure involves the following processing: overscan subtraction, trimming, bias and dark subtraction, and flat fielding. The keywords to be set for controlling these options are listed in Table 3.3. Below we describe how the command will try to correct your data.

REDUCE/CCD will first identify the Association Table. From this table it gets the names of the input science frames. Next, it will try to find the master calibration frames listed in the table, and will create these if they do not exist yet. After having collected all required calibration data the input frame is checked for its exposure type. Obviously, a dark frame should not be flat fielded and hence the processing options for the dark exposures should be set differently than for the science frames. After having determined the processing options the actual processing starts.