This image is a screen shot of a FarSounder waterfall display found in our SPS product. The Waterfall display shows targets and signal along a given look direction as a function of time. Each vertical column of pixels represents the signal as a function of range for a single ping. Newest pings are at the right of the display. Older pings move to the left of the display. This display is very useful for human verification of automatically detected diver tracks.
This screen shot corresponds to the previous sector view display of a closed circuit rebreather diver and scuba diver pair. It shows reflections from the divers' support boat along with the two divers. In this scenario, the CCR diver and the scuba diver start together once dropped from the boat at nearly 500 meters range to the sonar. They then swim together until about 250 meters range. At this point, they split apart and the CCR diver continues closer to the pier. The scuba diver loiters for a few minutes before continuing to the pier.
In this scenario, the two divers started in only 3.5 meters of water. At approximately 300 meter range, the sea floor slopes down to 8-10 meters water depth.