Performance limits of high-resolution systems

This paper deals with the ability of a sensor array to resolve and/or locate closely spaced sources of random signals. The present paper calculates instrumentation-independent lower bounds on the rms error of source separation and explores its dependence on actual separation, array geometry, knowledge concerning nuisance parameters such as signal power levels, and uncertainties in array geometry or propagation conditions. By carrying average source bearing as an additional parameter it also addresses the localization problem, because average bearing and angular separation are related to separate bearings by a simple linear transformation.