A bound on diurnal error in predicted ranges of nearly geostationary satellites

The orbit of a nearly geostationary satellite may be determined from range observations at two ground stations. Ranges predicted from the determined orbit contain a diurnal error component corresponding to errors in the determined eccentricity and inclination. This paper derives a bound on the diurnal range error. It is shown that diurnal error decreases as the distance between the ground stations used to determine the orbit increases, and that separation in latitude reduces diurnal error more effectively than separation in longitude.