Design of Relative GPS Navigation System for Autonomous Rendezvous Docking of ETS-VII

Abstract

Engineering Test Satellite-VII (ETS-VII) successfully performed the first autonomous Rendezvous Docking (RVD) flight using Relative GPS navigation in the world. ETS-VII is a test satellite to perform in-orbit demonstration of the autonomous rendezvous docking technology. Relative GPS (RGPS) navigation which is a sort of differential GPS (DGPS) is used primarily in a relative approach phase (more than 500m from target satellite). In this paper, we will introduce the ETS-VII RGPS system design and results of ground tests before in-orbit experiment. Especially we will focus on the design of space-borne GPS receiver and RGPS navigation algorithm.