Astronomy related Utilities
Functions | |
cxdouble | giraffe_compute_airmass (cxdouble alpha, cxdouble delta, cxdouble lst, cxdouble exptime, cxdouble latitude) |
Compute the airmass for a given pointing direction and observing site. |
Detailed Description
TBD
Function Documentation
cxdouble giraffe_compute_airmass | ( | cxdouble | alpha, | |
cxdouble | delta, | |||
cxdouble | lst, | |||
cxdouble | exptime, | |||
cxdouble | latitude | |||
) |
Compute the airmass for a given pointing direction and observing site.
- Parameters:
-
alpha Right Ascension in degrees. delta Declination in degrees. lst Local sidereal time in seconds elapsed since sidereal midnight. exptime Integration time in seconds. latitude Latitude of the observatory site in degrees.
- Returns:
- The function returns the computed average airmass. In case an error occurred the returned airmass is set to -1.
The function calculates the average airmass for the line of sight given by the right ascension alpha and the declination delta. The latitude in degrees of the observatory site latitude, and the local sidereal time at observation start lst has to be given, as well as the duration of the observation, i.e. the exposure time exptime.
The airmass is computed using the approximations of Young (Young A. T., 1994, "Air mass and refraction", Applied Optics, 33, 1108-1110) and Stetson (Stetson P., 1987, PASP 99, 191).
Definition at line 185 of file giastroutils.c.