Before you start the MOS context you should have done the following preparations:
For the averaging of the frames you may want to use the command COMBINE/LONG from the context LONG. Now you can start the session with
Midas ...> SET/CONTEXT mos
The initialization of the keywords to their default values is done by
Midas ...> INIT/MOS
If you saved the results of an earlier reduction session with
Midas ...> SAVE/MOS session
you can now initialize these parameters again (and restore all auxiliary tables) with
Midas ...> INIT/MOS session
A demonstration of the package can now be obtained with
Midas ...> TUTORIAL/MOS
which has an automatic (default) and an interactive mode (first parameter) and also allows to look at selected parts of the package (second parameter). In order to create all necessary test data you should run it once automatically.
Most of the numerical parameters are normally set to ``sensible'' values (which only means that they looked reasonable to the people who wrote this context), but the keyword for object ( ) is empty since there are no sensible defaults for these data. This holds also true for other keywords, which are normally filled either from the headers of your object (etc.) frames or with the results of MOS commands. Thus for the very first try you should just fill in the keyword mentioned above and continue (example see below).
Midas ...> SET/MOS obj=fors0001
If you want to make sure that the setups of your files are all the same use the command CHECK/MOS.
If your data were not produced by FORS you may give the FITS keywords that should be compared in an ASCII file. The use is then
Midas ...> CHECK/MOS file
Now you may start the real business!