next up previous
Next: SLA_GMST - UT to GMST
Up: SUBPROGRAM SPECIFICATIONS
Previous: SLA_GE50 - Galactic to B1950

SLA_GEOC - Geodetic to Geocentric   

ACTION:
Convert geodetic position to geocentric.
CALL:
CALL sla_GEOC (P, H, R, Z)

GIVEN:

P D latitude (geodetic, radians)
H D height above reference spheroid (geodetic, metres)

RETURNED:

R D distance from Earth axis (AU)
Z D distance from plane of Earth equator (AU)

NOTES:
1.
Geocentric latitude can be obtained by evaluating ATAN2(Z,R).
2.
IAU 1976 constants are used.

REFERENCE:
Green, R.M., 1985. Spherical Astronomy, Cambridge U.P., p98.


next up previous
Next: SLA_GMST - UT to GMST
Up: SUBPROGRAM SPECIFICATIONS
Previous: SLA_GE50 - Galactic to B1950

SLALIB --- Positional Astronomy Library
Starlink User Note 67
P. T. Wallace
12 October 1999
E-mail:ptw@star.rl.ac.uk