Multi frequencies and bearing target motion analysis : Properties and sonar applications

Multi frequency lines, concurrently processed with bearing measurements, are widely used for passive sonar target motion analysis (TMA). This paper analyzes the impact of utilizing additional narrow band (NB) lines on the target range accuracy obtained after TMA. More specifically, the TMA range and velocity accuracy improvement that is obtained from adding multiple frequency lines is demonstrate mathematically. This is a new result, since to date this performance improvement has only been shown numerically via Monte Carlo simulations. Data recorded at sea is utilized to validate the results and demonstrate the improvement obtained by using additional frequency tracks in the TMA process. This is a good example of the benefit of the association and fusion of multiple frequency bearing tracks.