hide
Free keywords:
-
Abstract:
Precise satellite orbit determination is commonly carried out by exploiting range measurements between ground-fixed stations and Earth-orbiting satellites. During the last decade an increasing number of Earth satellites, operating mainly in low-orbit mode (LEO), are equipped with GNSS receivers thus enabling the linkage of different satellites in space via inter-satellite range measurements. The usage of such observations provides a compelling option for estimating the orbits of Earth satellites without the need to employ ground-fixed tracking stations. To explore the potential of this option, a simulator has been developed in SYRTE for studying the satellite-to-satellite orbit determination problem. The simulator is designed to deal with different satellite constellations and parameterization schemes by considering a variety of physical dynamical models for the orbital motion. Furthermore, a least-squares adjustment strategy is implemented on simulated satellite-to-satellite range measurements to estimate the initial conditions (positions-velocities) of the considered satellite constellation.Using the aforesaid simulator, our aim here is to investigate the orbit determination problem through inter-satellite range measurements between GNSS and LEO satellites. In the present study we chose to work with the combination of three different dynamical models, namely the central gravity field, the J2 acceleration force and the attractive forces coming from the planets and the Moon. The objective is to analyze the rank-deficiency of the normal equations system derived from different GNSS+LEO satellite constellations, and to assess the quality of the estimated state parameters (initial satellite positions-velocities) by applying different types of constraints to overcome the inherent datum deficiency of the underlying problem.
