Bearings-Only Maneuvering Target Motion Analysis from a Nonmaneuvering Platform

In bearings-only target motion analysis (BOTMA), the common hypothesis is that the observer maneuvers while the source is traveling according to a constant speed and course. But there is no reason that the roles of each protagonist cannot be exchanged. In this paper, we consider an uncommon scenario: the trajectory of the target is composed of two legs (i.e., a target brutally changes its heading while keeping its speed) and the observer does not maneuver. We prove that the trajectory of the target is observable under nonrestrictive conditions. A batch estimator is proposed, and its performance is compared with the classic Cramer-Rao lower bound (CRLB). Monte-Carlo simulations reveal the efficiency of the estimator. The robustness to a nonbrutal heading change is evaluated. Then an adhoc estimate taking the correct model into account is proposed and applied to simulated data. Again, its performance is compared with the CRLB, and its robustness is evaluated when the speed of the target changes. Finally, the respective performances of the target motion analysis (TMA) made by each mobile are compared.