Environmentally tolerant beamforming for high-resolution matched field processing: Deterministic mismatch

Abstract

Standard adaptive beamforming or matched field processing requires accurate replica fields finely gridded over the search parameter space for localization with sidelobe control. Multiple constraints to the maximum likelihood method (MLM) technique are introduced in order to construct a beamformer (MCM) more tolerant to environmental mismatch of a deterministic nature. The result is a plane-wave or matched field beamformer that accommodates some mismatch in the environment while still suppressing sidelobes. This beamformer maintains its localization and sidelobe control over a coarser grid of the search parameter space than the standard MLM beamformer which requires an extremely fine grid for localization and sidelobe control. Examples simulating the performance of the MCM beamformer for plane-wave and matched field processing for an Arctic environment are given.