High-resolution techniques for two-dimensional estimation of angle-of-arrival for planar arrays

Two-dimensional beamforming can be a valuable technique for obtaining pure-mode signals in a multipath environment, if adequate resolution is available in both elevation and azimuth dimensions. Early simulations have shown that, for adequate signal/noise ratios and for selected signal and noise types, two sources separated by as little as .01 conventional beamwidth can be resolved. Thus, current arrays may still have adequate aperture for resolving such multipaths. The MUSIC algorithm and related eigenvalue/eigenvector analysis techniques appear to be the key to allowing the kind of superior performance which would eventually lead to an order-of-magnitude improvement in source-location accuracy.