Integrated Hardware Investigations of Precision Spacecraft Rendezvous Using the Global Positioning System

A closed-loop spacecraft rendezvous simulation facility was constructed and con gured to evaluate a newly developedrelativenavigationalgorithmthatprocesses the observablesoftheglobalpositioningsystem.Theprimary objective of this effort is to establish the performance of the integrated guidance and navigation architecture for autonomous rendezvous in low Earth orbit. A fundamental component of the relative navigation system is a real-time recursive extended Kalman lter. To achieve very precise relative navigation, the lter processes double-differenced carrier-phase measurements. Based on the lter state, all of the maneuvers are computed onboard by solving the Lambert targeting problem. The closed-loop simulation investigations show that 3.5 cm or less relative positioningaccuracy and 1.0mm/s relative velocity estimation accuracy are achievable in the absence of multipath. With these highlyaccurate relativenavigationresults, coordinatedandautonomousrendezvousmaneuversbecome possible