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SuperNOVAS v1.5
The NOVAS C library, made better
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Functions | |
short | ephem_close (void) |
short | ephem_open (const char *ephem_name, double *jd_begin, double *jd_end, short *de_number) |
short | planet_ephemeris (const double tjd[2], enum de_planet target, enum de_planet origin, double *position, double *velocity) |
SuperNOVAS planetary ephemeris manager for the planet_eph_manager()
and planet_eph_manager_hp()
functions.
This module exposes a lot of its own internal state variables globally. You probably should not access them from outside this module, but they are kept ad globals to ensure compatibility with existing NOVAS C applications that might access those values.
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
short ephem_close | ( | void | ) |
Closes a JPL planetary ephemeris file and frees the memory.
REFERENCES:
NOTES:
short ephem_open | ( | const char * | ephem_name, |
double * | jd_begin, | ||
double * | jd_end, | ||
short * | de_number ) |
This function opens a JPL planetary ephemeris file and sets initial values. This function must be called prior to calls to the other JPL ephemeris functions.
REFERENCES:
ephem_name | Name/path of the direct-access ephemeris file. | |
[out] | jd_begin | [day] Beginning Julian date of the ephemeris file. It may be NULL if not required. |
[out] | jd_end | [day] Ending Julian date of the ephemeris file. It may be NULL if not required. |
[out] | de_number | DE number of the ephemeris file opened. It may be NULL if not required. |
short planet_ephemeris | ( | const double | tjd[2], |
enum de_planet | target, | ||
enum de_planet | origin, | ||
double * | position, | ||
double * | velocity ) |
Retrieves planet position and velocity data from the JPL planetary ephemeris.
(If nutations are desired, set 'target' = 13; 'center' will be ignored on that call.)
REFERENCES:
tjd | [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 in the TDB or "T_eph" time scale. | |
target | The integer code (see above) for the planet for which coordinates are requested, e.g. DE_JUPITER. | |
origin | The integer code of the planet or position relative to which coordinates are measured. | |
[out] | position | [AU] Position vector array of target relative to center. |
[out] | velocity | [AU/day] Velocity vector array of target relative to center. |