Can you track the tracker?

A two-dimensional target can be effectively and efficiently tracked from angle-only measurements only if the observing platform is sufficiently maneuvering. Covert passive sonar TMA problem is a common application, and, for that, a two-leg platform pattern is appealing both in observability and simplicity. Now, suppose communication relating to the platform´s estimate of the target is intercepted by the target: Can the target therefrom infer where the (covert) platform must have been? This paper both answers the question and gives algorithms to solve it.