Effect of course maneuvers on bearings-only range estimation

The Cramer-Rao lower bound (CRLB) is used to examine the relative merits of tracking strategies in bearings-only target motion analysis. A formula is derived for the expected range error from a maximum-likelihood estimator (MLE) for the long-range situation. Monte Carlo simulations, with respect to the measurement noise, are used to show that for small amounts of noise the variance of the MLE range estimate follows the CRLB. It is also shown that there are often broad ranges of course changes for which acceptable ranging solutions can be found and large intervals of ownship course changes that should be avoided for target-motion analysis (TMA) range estimates.>