public void Terra( OnSurface Location, double St, ref double Pos, ref double Vel )
Public Sub Terra ( Location As OnSurface, St As Double, ByRef Pos As Double(), ByRef Vel As Double() )
public: virtual void Terra( OnSurface Location, double St, array<double>^% Pos, array<double>^% Vel ) sealed
This function ignores polar motion, unless the observer's longitude and latitude have been corrected for it, and variation in the length of day (angular velocity of earth).
The true equator and equinox of date do not form an inertial system. Therefore, with respect to an inertial system, the very small velocity component (several meters/day) due to the precession and nutation of the Earth's axis is not accounted for here.