GPS Receiver Architecture and Expected Performance for Autonomous Navigation in High Earth Orbits

Abstract

ABSTRACT: GPS is an enabling technology for autonomous spacecraft navigation, including mission concepts involving formation flying in highly eccentric orbits. However, to date most spaceborne GPS applications have been limited to low earth orbits or postprocessing applications. This paper describes the problems associated with using GPS in the high earth orbit (HEO) environment and presents a GPS receiver design optimized for these applications. The design builds upon the PiVoT receiver developed by Goddard Space Flight Center by incorporating the GPS Enhanced Orbit Determination (GEODE) navigation filter, a high-quality clock, and enhancements to basic receiver acquisition and tracking algorithms. Predicted navigation performance for several representative missions, including geosynchronous and geosynchronous transfer orbits, is presented. The analysis shows that a modest reduction in the acquisition threshold of the receiver enables reliable navigation performance even in very high orbits with unfavorable antenna placement restrictions.