A planar antenna for omnidirectional GMTI radar

For airborne surveillance and early warning radars 360/spl deg/ coverage is a desirable feature. Future military airborne radars will have omnidirectional coverage combined with ground moving target indication (GMTI) capability, for instance by using STAP (space-time adaptive processing) for detection of slow moving targets. In this contribution a randomly thinned array antenna for use with STAP is proposed. For achieving 360/spl deg/ azimuthal coverage subarrays including dipoles with rotational symmetry are used. Real-time STAP processing is achieved by using an overlapping subarray concept. It can be shown also that range ambiguous clutter returns are cancelled through vertical nulling. The slow target detection performance is analysed, and the directivity patterns are shown.