Showing papers on "Adaptive beamformer published in 1971"

Adaptive beamformer with time constant control

Abstract: An adaptive beamformer and signal processor for sonar and other signal receptor arrays, in which beamforming is accomplished by correlation feedback loops providing matched weighting across the array. For improved performance of the adaptive beamformer thus comprised in the presence of large input transients, while preserving its steady state performance essentially unchanged, the time constant of the correlation feedback loops is placed under automatic control and adjusted thereby to prevent saturation of the loops even with large interference transients.

Source Location with an Adaptive Antenna Array

Abstract: : An adaptive antenna array processing technique that allows a spatial signal field to be characterized in terms of multiple wavefronts in a background of spatially uncorrelated noise is presented. In particular, the array processor would provide simultaneous, real time, multisource positional location. The technique is interpreted in terms of an eigenvector decomposition of the single-frequency, spatial-correlation matrix of the data received at the spatial array of sensors. A relationship is established between a multiple wavefront signal field and the eigenvectors of the corresponding single- frequency, sensor-to-sensor, correlation matrix. Because of the orthogonality of the correlation matrix eigenvectors, the processor gives an interference- rejection capability that is useful when locating weak signal sources in the presence of strong interfering sources. Finally, an iterative-adaptive algorithm for the real-time implementation of the array processor is specified.