Amplitude Modulation of Acoustic Signals by Ocean Waves and the Effect on Signal Detection.

A study was conducted of the amplitude modulation of an acoustic signal forward scattered from a wind-generated, model ocean surface. The demodulated spectrum of the surface scattered sound was compared with the model ocean spectrum while varying the acoustic frequency and angle of incidence. Several methods of enhancing signal detection through a knowledge of the ocean spectrum were studied. The most promising of these shows potential gains of the order of three decibels when the received signal is weak and fluctuating greatly, as at a Lloyd Mirror minimum.