Adaptive Beampattern Control Via Linear and Quadratic Constraints for Circular Array STAP

摘要

A general framework for adaptive and non-adaptive space-time beampattern synthesis using quadratic beampattern constraints with linearly constrained minimum variance (LCMV) beamforming has been developed. Main beam and sidelobe pattern control is achieved by imposing a set of inequality constraints on the weighted mean-square error between the adaptive pattern and a desired beampattern over a set of angle-Doppler regions. An iterative procedure for satisfying the constraints is developed which can be applied as post- processing to standard LCMV beamformers. The algorithm is used to synthesize a nearly uniform sidelobe level quiescent pattern for the circular UHF electronically Scanned Array (UESA), and to control sidelobe levels for the same array in an adaptive manner. The technique has been generalized for general rank reducing transformations to reduce computational complexity. Performance results using data provided by Lincoln Lab show that under low sample support conditions, sidelobes can be effectively suppressed while maintaining high signal-to-interference plus noise ratio, and deep nulls on clutter and interferers.