SIDE SCAN SONAR
Side scan sonar creates a picture or an image of the sea floor. It measures the strength of how “loud” the return echo is, and paints a picture.
Hard areas of the sea floor like rocks reflect more sound and have a stonger or louder return signal than softer areas like sand. Areas with loud echoes are darker than areas with quiet echoes. Objects or features that rise above the sea floor also cast shadows in the sonar image where no sound hit. The size of the shadow can be used to guess the size of the feature.
Roll over the image above with your mouse to see a diagram of how side scan sonar works.