OPTIMAL TIME-DOMAIN BEAMFORMING WITH SIMULATED ANNEALING INCLUDING APPLICATION OF A-PRIORI INFORMATION

A fast simulated annealing algorithm is developed for an optimal time-domain beamformer. The optimal beamformer has greater resolution than the standard frequency-domain beamformers, which discard information by averaging the data to form a correlation matrix and remove degrees of freedom by collapsing the number of unknown parameters. The optimal ambiguity function uses the data in raw form and depends on all of the unknown source parameters. This approach is practical with simulated annealing. A specialized simulated annealing algorithm is required to search for the source bearings and time series because the parameters are analogous to a mixture of substances with different freezing points. Examples are presented to demonstrate that the optimal beamformer can be enhanced significantly with a priori information and to illustrate the effects of source level and bandwidth, noise level, array size, and number of sources. © 1990, Acoustical Society of America. All rights reserved.