Abstract:

During U.S. Navy undersea acoustic telemetry and ranging (telesonar) engineering tests, probe signals in the 8- to 16-kHz octave will be observed at various ranges and at various locales. Doppler spread and multipath spread will be measured for these waveforms as a function of time. In addition, simultaneous transmission of tonals will allow measurement of the correlation between fades at different frequencies, and hence the coherence bandwidth. Finally, ambient noise will be analyzed for insight into noise statistics and noise nonstationarity. The above information supports signal and receiver design by providing measured, as opposed to theoretical, channel characteristics. These data will also broaden the understanding of geographic and seasonal variabilty of undersea shallow-water channels. This paper describes procedures for extracting these channel statistics from recorded telesonar data. [Work supported by ONR-321.]