ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

1pUW14. Effect of forward-scattered signal on beam noise estimation in shallow water.

Yung P. Lee

John Hanna

Sci. Appl. Intl. Corp., 1710 Goodridge Dr., MS T1-3-5, McLean, VA 22102

In deterministic situations, adaptive processors resolve strong coherent interferers and eliminate their contribution at locations away from them. But, in operation, it is found that the beam noise away from strong interferers is affected by their presence. Stochastic mechanisms involved with the interferer's signal are assumed to be responsible for this behavior. A comparison of ocean data with a simulation has been made to illustrate the effect of the forward-scattered signal from the ocean surface on adaptive beam noise estimation in shallow water. The stochastic forward-scattering mechanism is dependent on the environment and its effect is apparently influenced by undersampling in the spatial aperture of the measurement array. The dependency of beam noise on waveheight and bathymetry have been observed.