ASTSN2RD

Name

astsn2rd

Purpose

Astrometry conversion from ($\xi$,$\eta$) to ($\alpha$,$\delta$)

Description

Standard coordinate conversion (see Smart, p283)

Calling Sequence

astsn2rd,xi,eta,racen,deccen,ra,dec

Inputs

xi - Coordinate in tangent plane (radians).
eta - Coordinate in tangent plane (radians).
racen - Right ascension of tangent point between plane and celestial
sphere (radians).
deccen - Declination of tangent point between plane and celestial
sphere (radians).

Optional Input Parameters

Keyword Input Parameters

ARCSEC - Flag, if set indicates that the input xi,eta values are in
arcseconds. Otherwise they need to be in radians. Does not
affect the output ra,dec.

Outputs

ra - Right ascension (radians)
dec - Declination (radians)

Keyword Output Parameters

Common Blocks

Side Effects

Restrictions

Procedure

Modification History

1997/04/05 - Written by Marc W. Buie, Lowell Observatory
2009/06/22, MWB, modified to eliminate numerical singularities
2010/12/10, MWB, added ARCSEC keyword