On the problem of fixed shading in conjunction with an optimal/Adaptive array processor

This paper investigates the effects of fixed shading that may be present either in the element data prior to adaptation, or intentionally imposed in the body of the adaptation mechanism of an optimal/adaptive array. It is shown that when there is no "useful signal" in the main beam appropriately applied fixed shading may improve the low level interference rejection capability of the adaptive process. However, when main beam signals are present, the fixed shading will destroy the performance of the adaptive processor even for small signal-to-noise ratios (SNRs).