v_orbit.c File Reference

Calculate the velocity of an orbit. More...

#include <math.h>
#include <stdlib.h>
#include "aephem.h"

Functions
void	ae_v_orbit (double jd_tt, const struct ae_orbit_t *orb, double v[])
	Calculate the velocity of an object as it moves in its orbit. More...

Detailed Description

Calculate the velocity of an orbit.

Function Documentation

void ae_v_orbit	(	double	jd_tt,
		const struct ae_orbit_t *	orb,
		double	v[]
	)

Calculate the velocity of an object as it moves in its orbit.

The difference in velocity between this and assuming a circular orbit is only about 1 part in 10**4. Note that this gives heliocentric, not barycentric, velocity.

Parameters

jd_tt	The Julian date in TT.
orb	Orbital elements for the object.
v	For returning the heliocentric, rectangular velocity, in AU per day.

References ae_kepler().

Referenced by ae_geocentric_from_orbit(), ae_geocentric_sun_from_orbit(), and aes_subobs_point().