It's missing one thing and that is the fact the the speed of sound in water is not a constant. Speed of sound varies with many factors, the major ones are depth, temperature and salinity. The real sea is actually composed of layers, each layer having a different speed of sound. So the statement in the patent that says you can compute travel time (and thus range) is not correct. Two way travel time is easily measured; converting that to a distance needs much more information.
Slashdot Mirror
It's missing one thing and that is the fact the the speed of sound in water is not a constant. Speed of sound varies with many factors, the major ones are depth, temperature and salinity. The real sea is actually composed of layers, each layer having a different speed of sound. So the statement in the patent that says you can compute travel time (and thus range) is not correct. Two way travel time is easily measured; converting that to a distance needs much more information.