Empirical observations of a sonar adaptive array

The responses of adaptive and conventional acoustic array processors using data acquired from an underwater environment are compared. The data from a horizontal planar array with omnidirectional elements are processed using frequency-domain and element-space techniques to estimate the azimuthal noise anisotropy and to contrast the effectiveness of each processor. Three beamformers are represented: the uniform amplitude shaded beamformer, a nonuniformly shaded beamformer and a fully adaptive processor which seeks to optimise array response by minimising the beampower.