GNSS-Based Orbit Determination for Highly Elliptical Orbit Satellites

Abstract: The Highly Elliptical Orbit (HEO) is useful for a Geostationary/Geosynchronous Transfer Orbit as the orbit can be designed to have a low altitude perigee at the initial orbit and a high altitude apogee at the final orbit of the transfer. Due to the long dwell time at the apogee, however, a study on the feasibility of an autonomous orbit determination for HEO satellites is needed in order to fully take advantage of this. It is envisaged that spaceborne receivers for the current (GPS and Glonass) and upcoming GNSS systems (such as Galileo and Compass) will improve the GNSS-based orbit determination of HEO satellites. This paper investigates the potential of HEO satellite orbit determination using the multi-GNSS constellation, i.e. current 31 GPS satellites, assumed 24 Glonass satellites, planned 30 Galileo satellites and 27 Compass satellites. This paper first reviews the use of pseudorange measurements for orbit determination over the last two decades. Secondly, the paper describes the basic navigation requirements associated with using multi-GNSS in the HEO environment. It is assumed that a multi-GNSS receiver will receive all the signals from all the GNSS systems and utilise pseudorange measurements. The paper presents a navigation algorithm based on a Kalman filter, the state vector of which consists of position and velocity corrections to the nominal reference trajectory and the clock biases. The state vector is then propagated using the orbit and clock dynamics, and updated by th