LIST OF VALUES FOR HDUCLASn KEYWORDS




Date of last update: 23-Feb-94
By: M. F. Corcoran
(Values followed by * have been proposed but not ratified by the OFWG)


HDUCLASS: keyword which is used to specify the author(s) of the file format, eg:
HDUCLASS= 'OGIP ' / format conforms to OGIP standard


HDUDOC: keyword which is used to specify the document in which the format is defined. Its value is a string and is not necessarily meant to be interpreted by software. eg:
HDUDOC= 'Angelini et al. 1993, Legacy 3, p 32.'


HDUVERS: keyword used to specify the version of the format definition document used. Its value is a string, and it should be software-interpretable so should be simple to parse. Values should be of form X.Y.Z, where X, Y, and Z are integers, with the following understanding:
    change in X: format has been completely redefined - software take note
    change in Y: bug fix or new keyword(s) added which may impact software
    change in Z: minor change, no impact on software
    
Eg:
HDUVERS = '1.5.0 ' / version of format



Each document which specifies or describes a standard format should include values of HDUDOC and HDUVERS. The following assumes
HDUCLASS = 'OGIP ' / format conforms to OGIP standard


Table of Defined HDUCLASn Values

n=1 2 3 COMMENTS
EVENTS     Conforms to format defined in "The Proposed Timing FITS File Format", Angelini, Pence and Tennant (1993), and "The Recommended Columns and Keywords for a FITS Event List", Pence and George (1995, Legacy 6, 36)
  ALL   Photon Event List, includes all photons detected without screening
  ACCEPTED   Only accepted photons included in table
  REJECTED   Only rejected photons included in table
       
LIGHTCURVE     conforms to format defined in "The Proposed Timing FITS File Format", Angelini, Pence and Tennant (1993).
  TOTAL   Source + background lightcurve
    RATE values in each bin in table given in counts per time interval
    COUNT values in each bin in table given in counts per bin
  BKG   Background lightcurve
    RATE values in each bin in table given in counts per time interval
    COUNT values in each bin in table given in counts per bin
  NET   Source lightcurve after background subtracted
    RATE values in each bin in table given in counts per time interval
    COUNT values in each bin in table given in counts per bin
  EXPOSURE   exposure times vs. time
       
TEMPORALDATA     any table of non-science quantities vs. time Should conform to guidelines given by Angelini, Pence and Tennant (1993) where possible.
  HKP   housekeeping parameters
    COMPRESSED1 in compressed format
  TSI   temporal status indicators
    COMPRESSED1 in compressed format
  ASPECT   spacecraft aspect data
  EPHEM   spacecraft orbit information
  EVRATE   accepted, rejected particle event rates, master veto rates, etc.
    COMBINED2 in compressed format
       
GTI     "Good Time Intervals"; see Angelini, Pence, and Tennant (1994)
  STANDARD   acceptable science times screened by standard quality flags/limits; at minimum giving start and stop time for interval
  ALL   science time without regard to quality flags/limits; at minimum giving start and stop time for interval
       
SPECTRUM     conforms to "The OGIP Spectral File Format", Arnaud, George and Tennant (1992) and George and Arnaud (1992)
  TOTAL   gross spectrum (source + bkg)
    RATE values in each spectral bin in table given in counts per time interval
    COUNT values in each spectral bin in table given in counts
    PHOTON values in each spectral bin in table represent the Photon spectrum
  NET   spectrum of source after subtracting background
    RATE values in each spectral bin in table given in counts per time interval
    COUNT values in each spectral bin in table given in counts
    PHOTON values in each spectral bin in table represent the Photon spectrum
  BKG   spectrum of background
    RATE values in each spectral bin in table given in counts per time interval
    COUNT values in each spectral bin in table given in counts
    PHOTON values in each spectral bin in table represent the Photon spectrum
  DETECTOR   Detector extension for gross, source or bkg spectrum
       
IMAGE     2-D image array
  TOTAL   Gross image (no background subtracted)
  NET   image after subtracting background
  EXPOSURE   exposure map
  DETMAP   map of detector focal plan
  BKG   background image
  GENERIC   general image
  PRF   image of the point response function
    PREDICTED theoretical model of the instrument PRF
    TOTAL total image of instrument PRF, including background
    NET NET image of instrument PRF, including background
  VIGNETTING   image of vignetting in the focal plane
       
SRCLIST     list of derived source characteristics Conforms to "Rationalized Data Files: an Approach to a Multi- Mission Data Format for High Energy Astrophysics", Corcoran et al. 1993
       
RESPONSE     Conforms to "The OGIP RMF & ARF File Formats", George et al. 1992 and George and Arnaud (1998)
  EBOUNDS   specifies energy boundaries for response matrix.
  SPECRESP   extension contains spectral response vs. energy
  RSP_MATRIX   detector photon redistribution matrix
    REDIST detector photon redistribution matrix without any other corrections
    FULL detector photon redistribution matrix with all corrections (detector effective area, vignetting, etc.) included
    DETECTOR detector photon redistribution matrix with all detector corrections but no corrections for any other optical elements (XRT, filters, gratings, etc.)
       
ARRAY* TOTAL COUNT a FITS table that contains one or more arrays of data binned in 2 dimensions The coordinate axes may be time, energy, wire position lag, frequency, phase or delta t. (ADDED 22-Feb-94, XTE, Rots)

1NOTE: COMPRESSED form means that entries in the table only list the name of the parameter, the time of the parameter change, and the value of the parameter at that time. Otherwise, the table contains a TIME column and 1 column for each parameter of interest.

2NOTE: COMBINED form has been adopted to describe tables containing HK type data as well as science data, given in time order. Within the FITS file each row can contain scientific data (either intensity over an energy range or spectrum integrated over a delta time) and/or the HK type parameters given as an array within a column. Adopted within the SSS raw data FITS file




Page Author: Michael F. Corcoran

Last modified 2002-01-06