>Sea level is actually an expression of the mass of the Earth. The
>overall mathematical generalized formula to describe the Earth is an
>oblate spheroid. However, this is a generalized formula and not the
>actual shape.

Even the shape of the satellite antennae may change. Maybe one way of
handling the problem is to calculate the max radius of the Earth, the min
radius of the earth, then calculate the delta of the spread. If its not
much then use the avg radius + or - delta. There's always going to be error
somewhere.


Peter
"Through our efforts, oneness perfects itself"
 Idoru by William Gibson