XMM-Newton Science Analysis System


omflatfield (omflatfield-2.7) [xmmsas_20230412_1735-21.0.0]

Algorithm

subroutine omflatfield

   read in task parameters

   open OM OSW Image file

   determine file type from datamode in primary header

   read in the science window keywords from the primary header

   calculate image binning

   extract window data from MODES binary table extension

   extract OM OSW Image

   open OM Tracking History Data Auxiliary file

   determine file type from datamode in primary header

   extract tracking history data from OMTHX1 binary table extension

   check for poor tracking solution and warn

   extract OM In Orbit Flatfield file

   calculate maximum drift in x and y

   extract localised in orbit flatfield

   oversample localised in orbit flatfield

   loop over tracking frames to construct oversampled tracking shifted flatfield

      loop over discretised tracking steps

         add shifted oversampled localised in orbit flatfield to oversampled tracking shifted flatfield

      end loop

   end loop

   normalise the summed flatfield

   resize oversampled tracking shifted flatfield

   divide OM OSW Image by tracking shifted flatfield

   resize and rebin OM OSW Image with appropriate binning factors

   create output OM OSW Image file

   create output OM PPS flatfield

end subroutine omflatfield