Abstract
Shallow water ocean acoustic environments are challenging due to their multi-path arrival structure and the various Doppler processes that are associated with platform motion and surface interactions. For moving platforms, each acoustic arrival exhibits a Doppler offset that can be quite significant, which results in an overall response that is doubly spread, one which disperses signals in both time and frequency. A virtual ocean acoustic laboratory based on the Bellhop ray tracing model is used to study the distortion of broadband waveforms through dynamic shallow water ocean acoustic environments. Acoustic response functions are presented in order to illuminate the challenges posed by shallow water environments and mobile platforms. The shared Doppler process of the arrivals is illustrated in order to illuminate the value of bulk Doppler compensation schemes. This virtual acoustic laboratory is used to test spread spectrum communication performance at very low SNR. Bulk Doppler compensation schemes derived from joint estimation of symbols and the acoustic response are compared to the actual path dilation processes. Simulation results are presented for fixed source with moving receiver shallow water environments at diverse center frequencies and bandwidths.