Using interactions between features on a superdirectional sonar to find wrecks

A DERA classifier has been interfaced to a recreational sonar form Echo Pilot to provide a wreck location capability. In normal use, a single forward-looking beam plots the seabed contour by using super-directional techniques. The sonar monitors the amplitude of received echoes, and when this exceeds a given threshold it computes the inclination corresponding to the echo. The classifier uses the original data streams, and converts them to feature values on each ping; new classes of features have been developed to augment those usually used on A-scans.