Multiple-input–'multiple-output radar multistage multiple-beam beamspace reduced-dimension space-time adaptive processing

Multistage multiple-beam (MSMB) reduced-dimension (RD) space-time adaptive processing (STAP) algorithm for multiple-input–multiple-output radar has been proposed to reduce ground clutter in an airborne radar system. It is demonstrated that the MSMB RD STAP can reduce the degrees of freedom much less than the rank of clutter or minimum amount of channels of other RD algorithms without significant loss, exhibiting rapid convergence to the performance bound set by the optimum filter. The proposed algorithm provides the upper-bound output signal-to-interference-noise for RD STAP algorithm with fixed number of auxiliary channels, and it can use less auxiliary channels to achieve comparative performance. Consequently, the real time computation complexity of estimation and inversion of localised clutter covariance matrix is reduced, and the requirement of the sample support used to estimate the localised clutter covariance matrix is also reduced.