The first thing you will be asked by the script is the DOL of the Observation Group you want to
work with. During the creation of this group, you have specified the list of the science windows
you want to work with and they were attached to the created Observation Group. During script
runs, the newly created files will be attached to the Observation Group.
IC Master Group
To analyze your scientific data you also need to specify the location of the files with Instrument Characteristics (IC), such as the instruments calibration, instrument responses, instrument background etc. These files can exist in different versions - for example if you are trying to apply different algorithms and to check which one is better. The version number is reflected by the value of the VERSION keyword in the header unit of the corresponding FITS file. If the chosen algorithm makes use of the parameters varying with time then with its help several files will be produced, each valid for a given period of time indicated with the STRT_VAL and END_VAL keywords. The numbers in the name of the FITS file reflects neither the version number, nor the time period but only the order they were added to the database.
In order to avoid entering the location of the tons of IC files by hand the IC Master Group was created. One of the members of this group is a version table specifying which version of each IC file should be used in analysis. In principle, it is possible that for different purposes different sets of versions are preferable. In this case, this table will have several rows with different MNEMONIC names and for this reason such a name should be specified in the script along with the location of the IC Master Group. If these parameters are specified, then the IC master Group returns to the script the location of the IC files with a corresponding version and the time period corresponding to the science window under the analysis.
Calibration data
Besides the location of Science Data and IC files, location of the calibration data, provided by the system of on-board calibration sources, should also be specified. The time history of these data is not connected with the science windows and thus, these data are not attached to the Science Window Group.
Reference Catalog
The next thing that you should specify is the DOL of the reference catalog. This catalog will be used by the analysis software as a starting point which increases the speed of the source location. As a result of the analysis, a new catalog based on the analyzed sky region will be produced.
Parameters not connected with the file locations
And of course in the script parameter file you should specify such parameters as: aim of analysis, desired energy ranges, background fitting method, etc. The detailed description of the parameters are given in the instrument specific user manuals [1,2,3,4], see chapters Scientific Analysis and Cookbook.