A method for automatic detection of underwater objects using forward-looking imaging sonar

A method for automatic detection or recognition using high-frequency forward-looking imaging sonar is proposed. The method includes segmentation of an underwater object´s echo shape or its acoustic shadow shape. For accuracy of segmentation, some constraints were assumed on the underwater ground and the sonar´s pose. The separated shape was compared to simulated reference shapes to know its orientation or identity by the shape matching method that use shape context concept. An experiment conducted in a wave tank validated the method qualitatively. The method can be applied to an AUV´s object-searching applications.