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Sidescan Sonar Image Processing:Correcting Brightness Variation And Patching Gaps, Yet-Chung Chang, Shu-Kun Hsu, Ching-Hui Tsai

Journal of Marine Science and Technology

Sidescan sonar data are typically presented as gray level images. However, sidescan images often show striking variations in brightness. These variations, caused by the sonar beam pattern and the constantly changing attitude of the towfish, make the images difficult to read as pictures of the seabed. This reduces the utility of the images for marine geologists. In this paper, the effects of the sonar beam pattern across the swath are corrected using a normalization process based on the average signal intensity for each grazing angle. Noise along the track, which is generally caused by changes in the attitude of the …