Where do we stand on high resolution in low-angle tracking radar?

Summary form only given. Various issues involved in the achievement of high resolution in low-angle tracking radar are reviewed. Particular attention is given to the multipath phenomenon, the use of high-resolution beamforming, estimation techniques, nonredundant arrays, results obtained with a multiparameter adaptive radar system, and future plans for adaptive matched illumination and adaptive diffuse multipath cancellation/modeling.<>