solsys2.c File Reference

Functions
void	jplihp_ (const double *jd_tdb, long *targ, long *cent, double *posvel, long *err_flg)
	Function prototype for the FORTRAN subroutine jplihp in jplint.f.
void	jplint_ (const double *jd_tdb, long *targ, long *cent, double *posvel, long *err_flg)
	Function prototype for the FORTRAN subroutine jplint in jplint.f.
short	planet_jplint (double jd_tdb, enum novas_planet body, enum novas_origin origin, double *position, double *velocity)
short	planet_jplint_hp (const double jd_tdb[2], enum novas_planet body, enum novas_origin origin, double *position, double *velocity)
short	solarsystem (double jd_tdb, short body, short origin, double *position, double *velocity)
short	solarsystem_hp (const double jd_tdb[2], short body, short origin, double *position, double *velocity)

Detailed Description

Author

G. Kaplan and A. Kovacs

SuperNOVAS major planet ephemeris lookup wrapper for JPL ephemerides accessed over pleph(). It is a top-level wrapper, with an intermediate Fortran routine, jplint_() providing the interface between the NOVAS planet calculator functions here and the pleph() call of the JPL library. (The sample source code of jplint.f is included in the distribution).

For supporting JPL ephemerides more generally, including for satellites, asteroids, and comets, you are probably better off using planet_ephem_provider(), and provide an interface, e.g. to the SPICE library, via novas_ephem_provider instead, which you can then activate at runtime with set_planet_provider().

Based on the NOVAS C Edition, Version 3.1:

U. S. Naval Observatory
Astronomical Applications Dept.
Washington, DC
http://www.usno.navy.mil/USNO/astronomical-applications

See also

solarsystem.h

solsys-calceph.c

solsys-cspice.c

Function Documentation

planet_jplint()

short planet_jplint	(	double	jd_tdb,
		enum novas_planet	body,
		enum novas_origin	origin,
		double *	position,
		double *	velocity
	)

Obtains planet positions via the JPL direct-access solar system ephemerides, wtih normal (reduced) precision – typically good to the milliarcsecond level.

It generalizes access to the JPL software by calling a Fortran interface subroutine, 'jplint', instead of making a direct call to the JPL subroutine 'pleph', whose arguments have changed several times throughout the years. This way, any future change to the arguments can be accommodated in 'jplint' rather than in this function.

For supporting JPL ephemerides more generally, including for satellites, asteroids, and comets, you are probably better off using planet_ephem_provider(), and provide an interface, e.g. to the CSPICE library, via novas_ephem_provider instead, which you can then activate dynamically with set_planet_provider().

REFERENCES:

1. JPL. 2007, JPL Planetary and Lunar Ephemerides: Export Information, (Pasadena, CA: JPL) http://ssd.jpl.nasa.gov/?planet_eph_export.
2. Kaplan, G. H. "NOVAS: Naval Observatory Vector Astrometry Subroutines"; USNO internal document dated 20 Oct 1988; revised 15 Mar 1990.

Parameters

	jd_tdb	[day] Two-element array containing the Julian date, which may be split any way (although the first element is usually the "integer" part, and the second element is the "fractional" part). Julian date is on the TDB or "T_eph" time scale.
	body	Major planet number (or that for Sun, Moon, SSB..)
	origin	NOVAS_BARYCENTER (0) or NOVAS_HELIOCENTER (1), or 2 for Earth geocenter – relative to which to report positions and velocities.
[out]	position	[AU] Position vector of 'body' at jd_tdb; equatorial rectangular coordinates in AU referred to the ICRS.
[out]	velocity	[AU/day] Velocity vector of 'body' at jd_tdb; equatorial rectangular system referred to the ICRS, in AU/day.

Returns

0 if successful, or else 1 if the 'body' or 'origin' argument is invalid, or else 2 if the 'jplint_()' call failed.

See also

planet_jplint_hp()

planet_ephem_provider()

set_planet_provider()

solarsystem()

Since

1.0

References jplint_(), NOVAS_BARYCENTER, NOVAS_HELIOCENTER, NOVAS_MERCURY, NOVAS_MOON, and NOVAS_SUN.

planet_jplint_hp()

short planet_jplint_hp	(	const double	jd_tdb[2],
		enum novas_planet	body,
		enum novas_origin	origin,
		double *	position,
		double *	velocity
	)

Obtains planet positions via the JPL direct-access solar system ephemerides, wtih high precision – typically good to below the microarcsecond level.

It generalizes access to the JPL software by calling a Fortran interface subroutine, 'jplint', instead of making a direct call to the JPL subroutine 'pleph', whose arguments have changed several times throughout the years. This way, any future change to the arguments can be accommodated in 'jplint' rather than in this function.

For supporting JPL ephemerides more generally, including for satellites, asteroids, and comets, you are probably better off using planet_ephem_provider(), and provide an interface, e.g. to the CSPICE library, via novas_ephem_provider instead, which you can then activate dynamically with set_planet_provider().

REFERENCES:

1. JPL. 2007, JPL Planetary and Lunar Ephemerides: Export Information, (Pasadena, CA: JPL) http://ssd.jpl.nasa.gov/?planet_eph_export.
2. Kaplan, G. H. "NOVAS: Naval Observatory Vector Astrometry Subroutines"; USNO internal document dated 20 Oct 1988; revised 15 Mar 1990.

Parameters

	jd_tdb	[day] Two-element array containing the Julian date, which may be split any way (although the first element is usually the "integer" part, and the second element is the "fractional" part). Julian date is on the TDB or "T_eph" time scale.
	body	Major planet number (or that for Sun, Moon, SSB...)
	origin	NOVAS_BARYCENTER (0) or NOVAS_HELIOCENTER (1), or 2 for Earth geocenter – relative to which to report positions and velocities.
[out]	position	[AU] Position vector of 'body' at jd_tdb; equatorial rectangular coordinates in AU referred to the ICRS.
[out]	velocity	[AU/day] Velocity vector of 'body' at jd_tdb; equatorial rectangular system referred to the ICRS, in AU/day.

Returns

0 if successful, or else an error code of solarsystem().

See also

planet_jplint()

planet_ephem_provider_hp()

set_planet_provider_hp()

solarsystem_hp()

Since

1.0

References jplihp_(), NOVAS_BARYCENTER, NOVAS_HELIOCENTER, NOVAS_MERCURY, NOVAS_MOON, and NOVAS_SUN.

solarsystem()

short solarsystem	(	double	jd_tdb,
		short	body,
		short	origin,
		double *	position,
		double *	velocity
	)

A default implementation for regular (reduced) precision handling of major planets, Sun, Moon and the Solar-system barycenter. See DEFAULT_SOLSYS in Makefile to choose the implementation that is built into with the library as a default. Applications can define their own preferred implementations at runtime via set_planet_provider().

Since this is a function that may be provided by existing custom user implementations, we keep the original argument types for compatibility, hence 'short' instead of the more informative enums).

Parameters

	jd_tdb	[day] Barycentric Dynamical Time (TDB) based Julian date
	body	Major planet number (or that for the Sun, Moon, or an appropriate barycenter), as defined by enum novas_planet, e.g. NOVAS_MARS (4), NOVAS_SUN (10) or NOVAS_SSB (0). (For compatibility with existing NOVAS C compatible user implementations, we keep the original NOVAS C argument type here).
	origin	NOVAS_BARYCENTER (0) or NOVAS_HELIOCENTER (1) relative to which to return positions and velocities. (For compatibility with existing NOVAS C compatible user implementations, we keep the original NOVAS C argument type here).
[out]	position	[AU] Position vector of 'body' at 'tjd'; equatorial rectangular coordinates in AU referred to the mean equator and equinox of J2000.0.
[out]	velocity	[AU/day] Velocity vector of 'body' at 'tjd'; equatorial rectangular system referred to the mean equator and equinox of J2000.0, in AU/Day.

Returns

0 if successful, -1 if there is a required function is not provided (errno set to ENOSYS), 1 if the input Julian date ('tjd') is out of range, 2 if 'body' is invalid, or 3 if the ephemeris data cannot be produced for other reasons.

See also

novas_planet

solarsystem_hp()

set_planet_provider()

place()

ephemeris()

References planet_jplint().

solarsystem_hp()

short solarsystem_hp	(	const double	jd_tdb[2],
		short	body,
		short	origin,
		double *	position,
		double *	velocity
	)

A default implementation for high precision handling of major planets, Sun, Moon and the Solar-system barycenter (and other barycenters). See DEFAULT_SOLSYS in Makefile to choose the implementation that is built into the library as a default. Applications can define their own preferred implementations at runtime via set_planet_provider_hp().

Since this is a function that may be provided by existing custom user implementations, we keep the original argument types for compatibility, hence 'short' instead of the more informative enums).

Parameters

	jd_tdb	[day] Barycentric Dynamical Time (TDB) based Julian date, broken into high and low order components, respectively. Typically, as the integer and fractional parts for the highest precision.
	body	Major planet number (or that for the Sun, Moon, or an appropriate barycenter), as defined by enum novas_planet, e.g. NOVAS_MARS (4), NOVAS_SUN (10) or NOVAS_SSB (0). (For compatibility with existing NOVAS C compatible user implementations, we keep the original NOVAS C argument type here).
	origin	NOVAS_BARYCENTER (0) or NOVAS_HELIOCENTER (1) relative to which to return positions and velocities. (For compatibility with existing NOVAS C compatible user implementations, we keep the original NOVAS C argument type here).
[out]	position	[AU] Position vector of 'body' at 'tjd'; equatorial rectangular coordinates in AU referred to the mean equator and equinox of J2000.0.
[out]	velocity	[AU/day] Velocity vector of 'body' at 'tjd'; equatorial rectangular system referred to the mean equator and equinox of J2000.0, in AU/Day.

Returns

0 if successful, -1 if there is a required function is not provided (errno set to ENOSYS), or some other error code (NOVAS C was not very consistent here...)

See also

solarsystem()

set_planet_provider_hp()

place()

ephemeris()

References planet_jplint_hp().