Abstract:
The ATOC AST measurements in July 1996 used simultaneous broadband waveforms in bands near 28 and 84 Hz to study frequency-dependent differences in long-range propagation. The low band was below the normal operating range of the Hydroacoustics HLF6 transducer. The nonlinearity of the source, driven exceedingly hard in the low band, generated the high band waveform. Both m-sequence based and prescription FM waveforms were used. The desired level in each band was 135 W. This paper describes the procedures used to generate the transmitted waveforms and to process the receptions for multipath travel times and modal analysis. [Work supported by the Strategic Environmental Research and Development Program through ARPA.]