Comments on "High-resolution frequency-wavenumber spectrum analysis"

Capon has described an estimator that can be used to discriminate between wavefronts incident upon an array of sensors from different directions. It is shown here that for a received field consisting of a single "signal" wavefront and an uncorrelated "noise" component, Capon's estimator displays less angular resolution than the conventional estimator when the amplitudes and the delays of the received wavefront are not known within a given tolerance.