Design of an Orbital Element Estimator Using Relative Motion Data

摘要

A relative orbital element estimator is designed using least squares estimation. Range and range rate measurements are taken and a vector of Delaunay elements, relative to an interceptor satellite, is estimated using the nonlinear least squares equation. The estimator incorporates a state vector coordinate transformation from relative position and velocity orbital elements. Two modes of the estimator program are designed, batch and sequential, where the sequential modes uses Bayes estimation. Three test cases are analyzed and indicate satisfactory performance. Problem areas include estimator dependence upon a highly accurate initial estimate of the element vector to start the estimation process. The orbits are restricted to noncircular for both satellites and the orbits must be non coplanar. Range and range rate data for the estimator are provided using a truth model. (Author)