SIXTH ANNUAL
ASAP '98 WORKSHOP

Some Improvements to
Dominant Mode Rejection
Adaptive Beamforming

Abstract Dominant mode rejection DMR is an approach to adaptive beamforming in which only the large eigenvalues are used. It has the advantage of requiring fewer snapshots due to the reduced degrees of freedom. Starting with DMR a modification is developed to improve robustness to signal mismatch. An approach to controlling the quiescent beam pattern that works for acoustic noise is also presented. The standard approaches fail because source array elements are usually spaced closer than one-half wavelength so that the noise is correlated.

These new approaches are illustrated with examples.