Orbit restitution capability of a multiple-antenna GNSS receiver on a highly elliptic orbit reaching above gnss altitude

Astronomical missions are often characterized by high altitude, highly elliptic orbits. We report on the results of a study on the orbit determination capability of a receiver equipped with several GNSS antennas on a 1,000 km by 25,000 km altitude orbit. Detailed visibility analysis shows how this antenna array can help extend the tracking periods to GNSS constellations. Account is taken of the side lobe radio link allowed by the real GPS antennas radiation pattern. High accuracy orbit determination in the few centimeters range is shown to be possible due to the smooth character of the force field, even in the presence of unmodeled attitude variations.