On The Role Of Adaptive Beamforming And Modern Spectral Estimation In High Resolution Microwave Imaging*

摘要

Modern spectral estimation techniques offer higher angular resolution than Fourier-based methods in microwave imaging with large phased arrays. Two problems limit the applicability of these methods. Both are solved bv data-adaptive feedback control of the weight vector of the array. The method is adaptive beamforming, developed for the radio camera. The problems are 1) intrinsic mechanical and electrical distortion in large systems of antennas and 2) the lack of spatial stationarity in the radiation field from near-field targets. The theory and experiments with aircraft imagery at X-band (3-cm wavelength) are presented.