A number of non-standard keywords has been used by ESO e.g. for
definition of frames acquired at the La Silla observatory. They are
given in Table 7.1.3 and should not be used with other
definitions. An extended set of FITS keywords are defined for
describing data from the VLT (see [7]).
FITS keyword | Data type | MIDAS descriptor | Remarks |
MJD-OBJ | Real | O_TIME(4) | Modified Julian Date of start of exposure |
TM-START | Real | O_TIME(5) | UT of start of exposure, in sec. after midnight |
TM-END | Real | - | UT of end of exposure |
EXPTIME | Real | O_TIME(7) | Exposure time in sec. |
RA | Real | O_POS(1) | Right Ascension in degrees |
DEC | Real | O_POS(2) | Declination in degrees |
POSTN-RA | Real | O_POS(1) | Right Ascension in degrees |
POSTN-DE | Real | O_POS(2) | Declination in degrees |
AIRMASS | Real | O_AIRM | Mean airmass of exposure |
FILENAME | String | FILENAME | Original file name |
ESO-LOG | String | ESO-LOG | Observing log |
Due to the freedom to use non-standard keywords it is important to know their exact definitions when transferring data between different systems.