High resolution adaptive beamforming for a three dimensional sonar imaging system

Investigates the use of adaptive beamforming techniques to increase the resolution of a sonar imaging system. The sonar hardware (FTV) developed by a group at the Scripps Institution of Oceanography uses eight transmit beams and eight receive beams, each of which is oriented in a slightly different direction, to image a volume using an 8/spl times/8 grid of beams in elevation and azimuth. Imaging currently performed with the FTV system is limited by a 2 degree resolution in both azimuth and elevation. Both a Bartlett beamformer and a minimum variance beamformer are applied to the FTV sonar system to increase resolution and reduce sidelobe interference. Through simulation it is shown that by using adaptive beamforming, the image resolution can be improved to 1 degree in azimuth and elevation. Adaptive beamforming is applied to real data made available by Jaffe et al. The beamformed results are compared to the original images of the FTV sonar system.