Potential direction-finding accuracy of systems with antenna arrays configured as a set of an arbitrary number of rings

Configurations of antenna arrays for direction-finding systems in the form of a set of concentric circumferences are considered. An estimate of the potential accuracy of the measured bearing, which was obtained using the Cramer-Rao lower bound, is proposed. It is shown that in the case of antenna-feeder systems with antennas distributed uniformly over each circle, the potential accuracy is independent of the direction from which the received signal arrives.