ASCA Processing Documentation

These pages document the standard processing of ASCA data done at the NASA Goddard Space Flight Center. You may also view a list of changes from previous versions.

Processing is done by a set of modular routines each of which performs a major processing step. This page shows the order in which these routines are called and provides links to more detailed information.

If you have questions that this document does not answer, you can contact ascahelp@athena.gsfc.nasa.gov.

Processing has a top level script:
process (version 3.2)
Set up for processing and call the subroutines which process the data

This script executes processing steps in the following order:

1. telemetry (version 3.0)
   Fetch the telemetry and attitude files.

2. aspecting (version 1.6)
   Calculate the aspect point from the attitude files.

3. readfrfs (version 3.2)
   Unpack the raw telemetry into FITS event and housekeeping files.

4. combine (version 2.1)
   Merge the event files created by frfread.

5. faint2bright (version 1.3)
   Convert FAINT mode files to BRIGHT and BRIGHT2 modes

6. linearize (version 1.7)
   Run ascalin to calibrate the unfiltered event files.

7. fixthings (version 1.5)
   Fix a number of possible spacecraft-related problems in the data.

8. makefilters (version 1.6)
   Create the filter files.

9. screen (version 4.2)
   Run xselect to screen out bad data.

10. images (version 2.8)
    Generate images and exposure maps

11. sources (version 2.4)
    Find sources in the observed fields of view

12. spectra (version 3.2)
    Extract PI spectra of source and background

13. lightcurves (version 2.1)
    Extract light curves for each source

14. sourceevents (version 1.2)
    Extract event files for each source

15. framedata (version 1.2)
    Extract FRAME mode data from the telemetry.

16. calsource (version 2.4)
    Extract GIS calibration source spectra

17. earthevents (version 2.1)
    Extract bright and dark Earth event files

18. information (version 1.6)
    Calculate various pieces of information

19. eventinfo (version 2.6)
    Create a descriptive list of all of the event files.

20. header (version 1.8)
    Create an HTML header page.

21. sourceinfo (version 1.1)
    Create an HTML page listing the detected sources

22. filelists (version 2.1)
    Make lists of the files to be distributed.

23. wrapup (version 2.0)
    Do a final wrap-up of all files.