Astronomical Applications Department, U.S. Naval Observatory - NOVASC (Page 14)

LOCAL_PLANET

short int local_planet (double tjd, short int planet, short int earth,
double deltat, site_info *location,

double *ra, double *dec, double *dis)

PURPOSE:
Computes the local place of a planet or other solar system body,
given the location of the observer.

INPUT
ARGUMENTS:
tjd (double)
TDT Julian date for local place.
earth (short int)
Body identification number for the Earth.
planet (short int)
Body identification number for desired planet.
deltat (double)
Difference TDT-UT1 at 'tjd', in seconds.
*location (struct site_info)
Pointer to structure containing observer's location (defined
in novas.h).

OUTPUT
ARGUMENTS:
*ra (double)
Local right ascension in hours, referred to mean equator and
equinox of J2000.
*dec (double)
Local declination in degrees, referred to mean equator and
equinox of J2000.
*dis (double)
True distance from Earth to planet in AU.

RETURNED
VALUE:
(short int)
0...Everything OK.
>0...Error code from function 'solarsystem'.

Discussion:

See the discussion for function topo_planet. Subroutine local_planet is identical to topo_planet in

input arguments and use. The local place is essentially the topocentric place expressed in the coordinate
system of standard epoch J2000.0.