Practical approach to observability of bearings-only target tracking

A simple and practical approach to observability analysis of bearings-only target tracking is developed. The emphasis is on discrete time cases. The uniqueness of this approach is that the observability properties are derived directly from the concise relationships between target bearings and the observability matrix, instead of the much more complicated relationships between own-ship state and the observability matrix. Some observability criteria are obtained very naturally using such an approach. Its potential in such applications as own-ship maneuver optimization and tracking algorithm development is also very prospective.