SOME QUICK AND EFFICIENT METHODS FOR BEARING-ONLY TARGET MOTION ANALYSIS

This work contains new batch processing estimation methods for a targe t's trajectory, assumed to be linear and uniform, based only on the ob servation of its bearings. In the first part, the observer is assumed to have constant velocity so that one can only estimate the target's m otion, up to a multiplicative constant. We parametrize this motion by three bearings at three judiciously chosen times, and propose some sim ple, quick, yet highly efficient estimators for them. In the second pa rt, the observer moves nonuniformly. We introduce a new quadratic esti mator similar to the pseudolinear estimator but that does not have bia s. From the first part's results, we further introduce, for the case i n which the observer's motion can be decomposed into a finite number o f constant velocity segments, two sets of quasi-sufficient statistics that permit considerable saving in computation with no significant los s of efficiency. Expressions for the covariance matrix of our estimato rs and for their Cramer-Rao bounds are also provided.