HDU classes¶
Following NASA’s recommendation
(see HFWG Recommendation R8),
a hierarchical classification is applied to each HDU within DL3 FITS files,
using the HDUCLASS
and HDUCLASn
keywords.
Some useful links from other projects:
- http://cxc.harvard.edu/contrib/arots/fits/content.txt
- https://heasarc.gsfc.nasa.gov/docs/heasarc/ofwg/docs/ofwg_recomm/r8.html
- https://heasarc.gsfc.nasa.gov/docs/heasarc/ofwg/docs/ofwg_recomm/hduclas.html
- http://www.starlink.rl.ac.uk/docs/sun167.htx/sun167se3.html
- https://confluence.slac.stanford.edu/display/ST/LAT+Photons
The different HDUs defined in the current specifications are listed here:
EVENTS
: Table containing the event lists. See EVENTS.GTI
: Table containing the Good Time Intervals (‘GTIs’) for the event list. See GTI.POINTING
: Table containing the pointing direction of the telescopes for a number of time stamps. See POINTING.RESPONSE
: Table containing any of the different instrument response function components defined in the specs. See IRFs.
The current HDU class scheme used is the following:
HDUCLASS
: General identifier of the data format. Recommended value: “GADF” (for “gamma-astro-data-formats”)HDUDOC
: Link to the DL3 specifications documentationHDUVERS
: Version of the DL3 specification formatHDUCLAS1
: General type of HDU, currently:EVENTS
,GTI
orRESPONSE
HDUCLAS2
: In case ofRESPONSE
type, refers to the IRF components stored within the HDU:EFF_AREA
,BKG
,EDISP
orRPSF
HDUCLAS3
: In case ofRESPONSE
type, refers to the way the IRF component was produced (POINT-LIKE
orFULL-ENCLOSURE
)HDUCLAS4
: In case ofRESPONSE
type, refers to the name of the specific format
HDUCLAS1 | HDUCLAS2 | HDUCLAS3 | HDUCLAS4 |
---|---|---|---|
EVENTS | |||
GTI | |||
POINTING | |||
RESPONSE | EFF_AREA | POINT-LIKE | AEFF_2D |
FULL-ENCLOSURE | AEFF_2D | ||
EDISP | POINT-LIKE | EDISP_2D | |
FULL-ENCLOSURE | EDISP_2D | ||
RPSF | FULL-ENCLOSURE | PSF_TABLE | |
PSF_3GAUSS | |||
PSF_KING | |||
PSF_GTPSF | |||
BKG | POINT-LIKE | BKG_2D | |
BKG_3D | |||
FULL-ENCLOSURE | BKG_2D | ||
BKG_3D | |||
RAD_MAX | POINT-LIKE | RAD_MAX_2D | |
INDEX | OBS | ||
HDU |