Angular Localization CRB of Scanning Radar by Virtual Array Projection

Constrained by the coarse angular resolution, the real aperture radar (RAR) typically suffers from low location accuracy. Superresolution methods have been proposed to improve its location performance by an enhanced radar image. However, the limit of angular location has not been fully investigated. In this paper, an angular deterministic (conditional) Cramer-Rao bound (CRB) of the RAR is deduced to describe the angular location error bound. First, a virtual array projection model is analyzed in spatial frequency domain, which normalize the signal model of different antenna types. Then, a general form CRB based on complex signal is deduced. Last, the result for a single target is illustrated to verify the deduced CRB. The bound is significant to the design of radar system parameters and superresolution methods.