|21 April 2013||
Without being clever, just removing the blue "hits" from the
we find that a pretty good representation of a fish, obtained via Feature-Based Passive sonar has been obtained on the first try.
Even under the limitations of Feature-Based Passive sonar, and without help from our bag of sonar-processing tricks, we compute those red dots which are, mostly, on the target. Additional points, improving the images, can be obtained by using more sensors.
Each grid line is 6 inches from a nearest neighbor. So, one can estimate the size of the little fish, seen at a range of 25 feet.
A side view of the fish is shown in the lower part of the picture. Its colored dots were computed using active sonar methods. The latest simulations program (May 2013) has no active sonar component, eliminating one source of possible programmer-error.
This animation suggests what we will be able to see by decoding echoes of actual clicks of a real dolphin.