Advances in sonar signal processing in the 90´s

Advances in sonar signal processing in this decade have been mainly in the application of sophisticated signal processing techniques to satisfy requirements that come from both industry and government. For example ocean bottom mapping needs drove the development of improved sidescan sonars that can produce high resolution images of the bottom. With high resolution images pattern recognition techniques have been able to classify bottom types automatically. But not all sonars produce high resolution images. Other sonar systems require longer range capabilities and therefore give up the ability to produce high resolution images. In this case other signal processing methods, some relying on neural networks, have been successful in classifying bottom types. This paper will describe requirements, sonar systems, and signal processing methods that were applied by the oceans community over the last 6 years satisfying technological challenges