High resolution sensor array signal processing in the beamspace domain: novel techniques based on the poor resolution of Fourier beamforming

The prospect of sensor array signal processing in beamspace, as opposed to element space, is proposed for the purpose of advantageously exploiting the poor resolution of classical beamforming to convert the element space data vectors to beamspace data vectors having a higher signal/noise ratio and a lower dimensionality. The higher SNR facilities sub-beamwidth resolution capability while the lower dimensionality serves to ease the computational burden typically associated with high-resolution algorithms. Two distinctly different element-space-to-beamspace transformations are presented. The primary application of interest is the low-angle radar tracking problem wherein two signals, the direct and specular path signals, arrive near broadside to the array within a beamwidth of each other