SCULIB_AIRMASS

calculate the airmass for a given zenith distance

Description:

This routine calculates the airmass corresponding to the input zenith distance. The airmass is just sec(Z) until it reaches 2, after which a more complex algorithm developed by Ian Coulson is used (it is described by comments in the code). There may be a discontinuity in returned airmasses around the value 2, I haven’t checked.

Invocation

CALL SCULIB_AIRMASS (Z, AIRMASS, STATUS)

Arguments

Z = REAL (Given)
zenith distance (radians)
AIRMASS = REAL (Returned)
airmass
STATUS = INTEGER (Given and returned)
global status

Copyright

Copyright ©1993-1999 Particle Physics and Astronomy Research Council. All Rights Reserved.