An Improved Method on Associating Ascending and Descending Passes of Observations

Abstract

Association of ascending and descending passes (A-D passes) in uncorrelated tracks (UCTs) is an efficient way to find out a “new” object and to generate its elaborate orbit sequence gradually. This paper proposes an improved method for A-D passes association problem. This method takes a three-level association structure; extensive filtering is performed in level 1 with time interval and orbital parameters a, i, Ω as decision variables; elaborate filtering is performed in level 2 with time offset and orbital parameters Ω, λ as decision variables; validating by orbit determination (OD) is performed in level 3 with OD residual as decision variable. The corresponding filtering thresholds depend mainly on sensor coverage in longitude, time interval of A-D passes, initial orbit precision, measurement error, model error, etc. Simulation analysis indicates that the method has satisfactory aspects in association accuracy, stability and efficiency.