Improved pre-Doppler STAP algorithm for adaptive clutter nulling in airborne radars

Many space-time adaptive processing (STAP) algorithms heave been proposed for clutter nulling in airborne radar systems. These algorithms use the spatio-temporal relationship of clutter to significantly reduce the degrees of freedom required by an adaptive processor. One significant family of algorithms is pre-Doppler (or adapt-then-filter), which involves adaptively processing small subsets of radar pulses and non-adaptively Doppler filtering the results. This paper presents a new pre-Doppler algorithm which offers significant performance improvements by allowing partial adaptivity of the constraint vector. The new approach provides improved SINR loss and narrower clutter notches.