The side scan sonar unit, which will be used to map the bottom topography, consists of several pieces. The torpedo-like sensing head, shown here, is towed behind or to one side of the survey vessel. Successfully lowered to the appropriate depth, the fish can be seen as it is towed alongside the ship. The acoustic signal, which is sent from the fish, bounces off the sea floor, and returns to the fish, is transformed into a digital image of the bottom. This electronic data is sent from the fish to this yellow box, which is a specialized waterproof personal computer.
Navigational control is provided by a satellite GPS, or global navigation system.
This unit receives signals from a number of satellites orbiting the planet, and accurately calculates the position of the Bellows. The positional data generated by the GPS is fed into the side scan sonar computer, and researchers can then use the computer to measure distance, area, height, and other such calculations of features visible in the image. This image shows the screen of the side scan sonar while it is displaying image data. The rocky limestone outcrops can clearly be seen on the bottom, to the left of the mouse arrow. The black and yellow vertical line represent the path of the Bellows and the side scan fish.