A Novel Method to Suppress Short-Range Clutter in Airborne Radar

This paper primarily addresses the short-range clutter (SRC) suppression problem in non-side-looking airborne radar systems. For a high pulse repetition frequency, the generation of range-ambiguous clutter in the short range will affect the clutter covariance matrix (CCM) estimation accuracy. In addition, the CCM estimation requires a large number of range cells, and the elevation angle of the SRC changes rapidly with the range. Unlike the former method to design a series of pre-space-time adaptive processing (STAP) elevation filters (EFs), in which each EF sets a single null at the elevation angle of the short-range cell, a new method is proposed to design the EF only once by forming a certain null width to suppress the SRC. The modified EF design is based on average sidelobe level (SLL) control and constructed as a convex quadratic program, which can be solved using the CVX toolbox. The simulation results demonstrate that the proposed algorithm can effectively eliminate SRC while reducing the system implementation complexity.