Spherical coordinates to Cartesian coordinates (single precision).
CALL:
CALL sla_CS2C (A, B, V)
GIVEN:
A,B
R
spherical coordinates in radians:
[α,δ]etc.
RETURNED:
V
R(3)
[x,y,z] unit
vector
NOTE:
The spherical coordinates are longitude (+ve anticlockwise looking from the +ve
latitude pole) and latitude. The Cartesian coordinates are right handed, with the x-axis at
zero longitude and latitude, and the z-axis at the +ve latitude pole.