pub fn position_velocity(
elements: &Elements,
epoch: CalendarEpoch,
scale: TimeScale,
frame: Frame,
) -> Result<([f64; 3], [f64; 3]), ReducedOrbitError>Expand description
Evaluate the model position and velocity at epoch in the requested frame.
Returns (position_m, velocity_m_s). ECEF velocity includes the
Earth-rotation transport term.