This is a first draft proposal of a pointing table. Please note that the format is likely subject to change.
POINTING extension is a binary FITS table that contains for a number
of time stamps the pointing direction of the telescopes. A pointing is here
defined as the centre of the field of view (or centre of the camera
coordinates). In reality, all telescopes may point to different positions
(for example for divergent pointing mode). The main purpose of the
extension is to provide time dependent information on how to transform
between celestial and terrestial coordinates.
See also HFWG Recommendation R3 for the OGIP standard.
TIMEtype: float64, unit: s
- Pointing time (see Time)
RA_PNTtype: float, unit: deg
- Pointing Right Ascension (see RA / DEC).
DEC_PNTtype: float, unit: deg
- Pointing declination (see RA / DEC).
ALT_PNTtype: float, unit: deg
- Pointing altitude (see Alt / Az).
AZ_PNTtype: float, unit: deg
- Pointing azimuth (see Alt / Az).
Mandatory header keywords¶
The standard FITS reference time header keywords should be used (see Formats).
GEOLONtype: float, unit: deg
- Geographic longitude of array centre
GEOLATtype: float, unit: deg
- Geographic latitude of array centre
GEOALTtype: float, unit: m
- Altitude of array center above sea level