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The CCD package is based on so-called data sets. A data set contains a science frame and all its associated calibration frames. In order to archive a maximum of efficiency the CCD package uses a simple and straightforward naming convention: the names of the data sets are identical to the names of the science frames. All relevant data sets are assumed to be contained in the association table, generated by the MIDAS Data Organizer.
By combining the calibration frames of a particular exposure type ( e.g. bias) the user can create a master calibration frame. In the CCD context master calibration frame must have a exposure type postfix describing the exposure type of the frame. The extension is obligatory. The first part can be any legal character string. Below follows a listing of calibration frames that currently can be handling in the CCD package. Between brackets is indicated which exposure extension for the master calibration frame is used.
Other calibration frames that can be used in the calibration process are:
As described above, the CCD package allows the use of any name for the calibration frames as long as the extension is present. However, to made the reduction of CCD frames as automatic as possible a naming scheme for the master calibration frames has been built-in that. It is based on the association of calibration frames with science frames as stored in the association table. In this scheme, the name of a master calibration frame is, except for the exposure type extension, identical to the name of the data set (science frame). Using this convention the system is able to create the master calibration frame from the calibration frames in the association table and associated with that data set.
As a example of the naming convention used in the CCD package, assume a science frame with the name susi010.bdf. The association table contains 5 bias frames associated with this science frame: susi021.bdf to susi025.bdf. Following the default naming scheme the COMBINE/CCD will use these five bias frames to create the master bias frame. The name for this frame will be susi010_bs.bdf, indicating that it is a bias frame constructed from the bias frames associated with data set susi010.
*** WARNING ***
It is highly recommended to use the naming convention as explained above. Using different names is dangerous and may lead to wrong results. In the automatic reduction procedure, that will be discussed below, the system uses this standard naming convention. When using the basic CCD commands, in particular the commands COMBINE/CCD and MKCAL/CCD other names can be chosen.