Abstract:

One advantage that three-dimensional multibeam imaging systems have over more conventional systems is that they have the potential to track many targets that are concurrently in their field of view. As such, the accurate estimation of both position and target strength are important data which can be derived from the echo responses of an active multibeam imaging system. An algorithm has recently been developed which can be used to obtain higher positional estimates for targets than available from the preformed beams of a given multibeam system (Fish TV). The method refines a least-squares residual of the amplitudes of a set of predicted data versus a set of observed data by adjusting the parameters of a model. The parameters are the position and target strength of the target. The least-squares norm results in a maximum likelihood estimator for position and target strength in high signal-to-noise. Two fortunate aspects of the algorithm are that it takes into account the geometry of the sonar system and also uses only the amplitude data. The special collection geometry and acquisition method make these features important.