Antenna Array Manifolds for High-Resolution Direction Finding

The antenna array manifold is central to high-resolution direction finding. The analytic manifold is defined here as the mathematical model of the array response calculated by solving the electromagnetic equations for the waves impinging on the array. Array manifolds commonly used in the array signal processing literature are approximations of the analytic manifold. This paper describes the characteristics of the analytic manifold and compares it with commonly used approximate manifolds. The impact of these approximations on the performance of direction-of-arrival estimation in challenging superresolution scenarios is evaluated by selected numerical examples.