A Maximum a Posteriori Approach to Beamforming in the Presence of Calibration Errors - Statistical Signal and Array Processing, 1996. Proceedings., 8th IEEE Signal Processing Workshop o

T h e performance of DF-based beamformers is seriously degmded in situations where the array is imprecisely calibrated, or when the spatial coherence of the signal wavefronts is perturbed. W h e n the calibration errors or perturbation m a y be characterized by a set of parameters drawn f rom a known Gaussian distribut ion, a max imum a posteriori ( M A P ) estimator m a y be used to separately estimate the directions of arrival and the perturbation parameters, resulting in essentially an on-line auto-calibration. This paper examines the improvement that results f rom using the MAP auto-calibrated steering vectors i n standard DF-based beamformers to estimate the received signal waveforms and suppress unwanted interference. FOT the special case of additive unstructured calibration errors and uncorrelated signals, i t i s shown that the M A P beamformer i s similar in form to so-called “subspace corrected’’ approaches.