Abstract:

The U.S. Navy is developing undersea acoustic telemetry and ranging (telesonar) technology using shallow oceans as the physical transmission channel. The telesonar signaling philosophy is to achieve high reliability by designing for anticipated time and frequency spreading in the bounded, nonstationary, forward-scattered transmission channel. Obtaining the time-variant acoustic impulse response of representative channels supports appropriate signal design. These data allow measurement of time and bandwidth coherence, and aid understanding of boundary effects. Also, convolving signal waveforms with the impulse response simulates the influence of the transmission channel. This paper examines candidate probe signals for acquiring bandlimited acoustic impulse responses of shallow ocean channels. These probe signals are intended for systematic sampling of various littoral channels during telesonar sea tests. [Work supported by ONR-321.]