On Radar DoA Estimation and Tilted Rotating Electronically Scanned Arrays

We consider DoA estimation in a monopulse radar system employing a tilted rotating array. We investigate the case of nonzero steering angles, in which case the mapping between the target's azimuth and elevation in the global coordinate system and their counterparts in the array local coordinate system becomes increasingly nonlinear and coupled. Since estimating the azimuth using coherently integrated signals might be difficult because of strong modulation in the difference signal induced by the rotation of the antenna, we develop an iterative approach that alternates between estimating the elevation using coherently integrated signals and estimating the azimuth using unfiltered signals. We also develop a simplified version of the scheme, which employs only one iteration and forms the final estimates by applying simple corrections to results of the first iteration.