All sidescan-sonar data were processed using USGS sidescan-sonar processing software packages XSonar and ShowImage.
A median filtering routine was applied to the sidescan-sonar data to remove speckle noise. Sonar data were further processed to correct for slant-range and radiometric distortion inherent in the sonar data. Sonar data were corrected for layback. All processed data were mosaicked using XSonar, resulting in an enhanced, geographically correct, sidescan-sonar mosaic with 1 meter/pixel resolution. The composite mosaic was converted to a TIFF image using the following LINUX commands:
rawtopgm -headerskip 80 14700 10400 mosaic.ras | pnmtotiff - > mosaic.tif
An associated TIFF world file was then created using GeoTiff Examiner