Extended Kalman filter-based precise orbit estimation of LEO satellites using GPS range measurements

Abstract

In order to meet the accuracy requirements of scientific mission applications of Low Earth Orbit (LEO) satellites, precise orbit solution with at least less than a meter accuracy at a fast update rate is required. To cater to these needs, this paper proposes a methodology for fast and precise estimation on ground, of orbits (position and velocity) of LEO satellites, based on Extended Kalman Filter (EKF) estimation technique using Global Positioning System (GPS) precise data products. For the proposed Precise Orbit Determination (POD) of LEO satellites, dual frequency code/carrier phase and single frequency code and carrier phase based GPS oneway range measurements are used. All the perturbation forces acting on a LEO spacecraft are modelled, and the errors in GPS measurements are modelled and removed. The proposed methodology when applied to the GPS receiver data of LEO satellites like GRACE, COSMIC, HYSIS, CARTO and MICROSAT resulted in cm level accuracy in position and mm/s level accuracy in velocity.