Adaptive space time processing for forward looking radar

In existing radar literature, STAP (space time adaptive processing) has been almost exclusively considered for clutter and jammer rejection in SLAR (sideways looking airborne radar) applications. In SLAR, the existence of a simple linear relationship between the clutter Doppler and angular location can lead to STAP solutions that theoretically achieve complete clutter suppression. In forward looking radar, since the same simple linear relationship no longer exists, it has generally been assumed that STAP can offer no significant performance advantage over a cascaded processor consisting of fixed (nonadaptive) clutter filtering followed by spatial adaptive beamforming. This paper shows that, contrary to this view, there are practical situations where an approximate linear relationship between mainlobe clutter Doppler and angular location can be exploited to positive advantage. Simulation results, comparing STAP with the cascaded approach in an AI (airborne intercept) application, are included.