Dynamic Model Fidelity Effects on Covariance Based Track Association

Abstract

This paper examines the performance of covariance-based track association with varying levels of dynamic model fidelity. To minimize the dynamic nonlinearities, the mean modified equinoctial (MME) elements are used. Ground-based radar measurements are generated by propagating the osculating orbits of 100 space objects in low Earth orbit using a 70×70 spherical harmonic gravity model (JGM-3). Atmospheric drag, solar radiation, and third-body gravity are not considered. To associate two tracks, the two sets of states and covariances are propagated to a common time. The Mahalanobis distance between the two tracks is then used to determine whether they associate. A higher-fidelity dynamic model for state propagation improves association performance, while the fidelity of the dynamic model for covariance propagation does not have a significant impact. The MME-based track association demonstrates excellent performance when incorporating J2, J22, J4, and J6 in the MME state propagation as well as the MME covariance propagation with J2. It achieves an accuracy of 99.92%, a true positive sensitivity of 92.43%, a false negative sensitivity of 7.57%, a false positive sensitivity of 0%, and a true negative sensitivity of 100% when associating tracks separated by 10 days.