SIMULTANEOUS ORBIT DETERMINATION WITH PHYSICAL CONNECTEDNESS

THE INNOVATION, CALLED SIMULTANEOUS ORBIT DETERMINATION, REFERS TO THE SEQUENTIAL SIMULTANEOUS ESTIMATION OF THE ORBITS OF TWO SPACECRAFT (SPACE SHUTTLE AND TDRSS) WHEN TRACKING MEASUREMENTS DEPEND SIMULTANEOUSLY ON BOTH ORBITS. SUCCESSFUL SIMULTANEOUS ORBIT DETERMINATION DEPENDS ON PHYSICAL CONNECTEDNESS. THIS REFERS TO THE USE OF PHYSICALLY CONNECTED MODELING OF RANDOM ACCELERATION ERRORS FOR THE PROCESS NOISE OF THE SEQUENTIAL ORBIT ESTIMATOR; AND IT REFERS TO THE USE OF PHYSICAL PROPERTIES ASSOCIATED WITH RANDOM PHENOMENA OF THE SYSTEM USED TO GENERATE THE TRACKING DATA. OBJECTIVES OF PHASE I ARE: (1) TO COLLECT APPROPRIATE LIVE DOPPLER-SUM TRACKING AND SUPPORT DATA; (2) CONSTRUCT AN EXPERIMENT DESIGN REPORT TO BE USED IN PHASE II TO DEVELOP A LIVE-DATA ENGINEERING TEST-BED. THE OBJECTIVE FOR PHASE II IS TO DEMONSTRATE SIGNIFICANT ORBIT DETERMINATION ACCURACY IMPROVEMENT FOR THE SPACE SHUTTLE ORBIT USING DOPPLER-SUM TRACKING DATA AND THE INNOVATIONS.