Performance characterisation of hybrid STAP architecture incorporating elevation interferometry

Abstract

Radar space-time adaptive processing (STAP) techniques have
classically focused on azimuth-Doppler adaptivity while placing minimal
emphasis on elevation. Elevation beamforming offers significant clutter
suppression improvement, allowing further suppression of interference
sources having identical Doppler and azimuth. This work incorporates
elevation adaptivity through an interferometric approach, greatly
improving clutter suppression while providing an often overlooked target
height discrimination capability. A mathematical construct encapsulating
the multistage processing framework is developed for the proposed
technique. This framework allows extension of the traditional factored
time-space (FTS) technique into the azimuth-Doppler-elevation hypercube
and represents a subclass of more generalised hybrid methods. The
proposed concept is validated through results based on simulated
airborne radar data. Target detection improvement of the order of 25 dB,
when compared to standard two-dimensional FTS processing, is
demonstrated for an 8 × 8 nonuniform rectangular array. Elevation
pattern data are provided to illustrate achievable null width/depth
capabilities. These data also indicate target height discrimination is
inherently provided and further development is warranted