Carrier Phase Differential GPS for LEO Formation Flying – The PRISMA and TanDEM-X Flight Experience

Abstract

The paper describes recent accomplishments in the field of carrier phase based differential GPS navigation of multiple spacecraft based on practical mission experience. Following long years of research and laboratory experimentation, the technology has ultimately found its way into orbit and constitutes an indispensable contribution to the first European formation flying missions. While TanDEM-X relies on a high-precision post-facto reconstruction of the relative spacecraft position for interferometric SAR processing, the PRISMA mission makes use of differential GPS for real-time navigation and orbit control. Actual flight data are presented along with a discussion of the achieved performance and current limitations.