I have untangled this mystery: it had dawned on me that in my latest simulations, redone to demonstrate Feature-Based Passive (FBP) methods, my arrays were of much smaller diameter than the previous ones - and I had very little clue what I had done to make this possible. I have solved this mystery and can now show how to make a sonar-array for imaging in the manner, if not the sophistication, of dolphins. The simulated array is about the size of the chin of a bottlenose dolphin.
Summer 2015. I am writing the strategic patent (application) that I call "Toascope," reflecting the use of times-of-arrival ("toas") of feature-of-waves at sensors in an array.
(That patent was submitted under the title Toascope: sonar and radar imaging inspired by dolphins, in July 2017 and, in the three years from 2014, I coded another simulator, invented the 3D streaming fish-finder, and submitted two other provisional applications for patent.)