At a single frequency an array's bearing-response pattern is expressed as a weighted sum of terms involving a steering matrix and the eigenvalues and eigenvectors of the array's spectral density matrix. This point of view is used to gain an understanding of the beam patterns generated by the Adaptive Search and Track Array (ASTA) processor. ADMINISTRATIVE INFORMATION This study was performed under NUEL Project No. A-415-00-00, "Multibeam Sonar Studies"(U), Principal Investigators, H. S. Newman and Dr. N. L. Owsley, NUSL Code 2242, and Navy Subproject and Task No. SF 11 121 103-12894, "Active Sonar Detectors and Classification Signal Processing" (U), Program Manager, K. Buske, NAVSHIPS00V1. The Technical Reviewer for this report was N. L. Owsley, Research Electronic Engineer in the Signal Processing Branch of the Information Processing Division.