palPv2ue palPv2ue - Universal elements to position and velocity

Description:
Construct a universal element set based on an instantaneous position and velocity.

Invocation:
void palPv2ue( const double pv[6], double date, double pmass, double u[13], int $*$ jstat );

Arguments:

pv = double [6] (Given)
Heliocentric x,y,z,xdot,ydot,zdot of date, (AU,AU/s; Note 1)
date = double (Given)
Date (TT modified Julian Date = JD-2400000.5)
pmass = double (Given)
Mass of the planet (Sun=1; note 2)
u = double [13] (Returned)
Universal orbital elements (Note 3)

  • (0) combined mass (M$+$m)

  • (1) total energy of the orbit (alpha)

  • (2) reference (osculating) epoch (t0)

  • (3-5) position at reference epoch (r0)

  • (6-8) velocity at reference epoch (v0)

  • (9) heliocentric distance at reference epoch

  • (10) r0.v0

  • (11) date (t)

  • (12) universal eccentric anomaly (psi) of date, approx

jstat = int $*$ (Returned)
status: 0 = OK
  • -1 = illegal PMASS

  • -2 = too close to Sun

  • -3 = too slow


Notes: