Reduced-Dimensional STAP Method for Nonstationary Clutter Suppression in Endfire Array Airborne Radar

An endfire array antenna has garnered significant attention in the field of airborne early warning (AEW) detection for its excellent characteristics, such as simple structure and low aerodynamic profile. Nevertheless, the endfire array airborne radar (EFAAR) encounters the challenge of suppressing powerful ground/sea clutter in practical applications, especially in nonstationary clutter environment. Although 3-D space-time adaptive processing (STAP) has demonstrated efficacy in nonstationary clutter suppression for side-looking array airborne radar (SLAAR), it is at the cost of huge computation load and training sample requirement. In this article, a 3-D reduced-dimensional (RD) STAP method is proposed to suppress the nonstationary clutter for EFAAR based on its clutter distribution. First, the 3-D space-time signal model for EFAAR is established, and the characteristics of the antenna pattern and the clutter are discussed in detail. Second, on the basis of the analysis, an RD method for 3D-STAP, which combines multiple channels in row and multiple beams in column, is proposed. Then, computation loads of the proposed method and the existing typical methods are analyzed in detail, and the performance of parameter estimation for EFAAR is also discussed. Finally, simulation results verify the feasibility and effectiveness of the proposed method and its advantage over the typical methods.