Algorithm

   subroutine omflatindex

     Check parameters

     if(mode == "create")

       Create index file

     else if(mode == "insert")

       Open index file
       Read date, observation ID from combined image files
       Calculate total counts in mod-8 images
       Find row index file to insert entry
       Insert entry
       Close index file

     endif

   end subroutine  omflatindex