A high maneuvering dim target detection algorithm based on non-uniform sub-aperture division and hybrid accumulation

高机动微弱目标非均匀分段混合积累方法

National Key Laboratory of Radar Signal Processing, Xidian University, Xi'an 710071, China

Received: 7 March 2024

Abstract

The motion state of highly maneuverable small target is complex, with weak scattering energy and difficulty in maintaining signal coherence over long integration time, resulting in ineffective accumulation of target echo signal. To address this issue, this paper proposes a hybrid accumulation algorithm for highly maneuverable small target in passive radar based on non-uniform sub-aperture division. Initially, the generalized binary method is employed to effectively partition the echo signal over long integration time into non-uniform sub-apertures, ensuring that the target signal energy within each sub-aperture is concentrated in the same range cell. Subsequently, the fractional order Fourier transform is utilized to correct for the energy migration of target echo signal across Doppler cells within the sub-apertures, achieving effective coherent accumulation of target signal within each sub-aperture. Finally, a dynamic programming algorithm is applied to complete the non-coherent accumulation of target signals between sub-apertures. Simulation experiments demonstrate that the proposed method can effectively accumulate the signal energy of highly maneuverable weak target under long integration time conditions, and its feasibility is verified through comparative experiments.

摘要

高机动弱小目标运动状态复杂、散射能量微弱、难以维持长积累时间的信号相干性, 从而造成目标回波信号无法有效积累。针对这一问题, 提出一种基于非均匀子孔径划分的外辐射源雷达高机动微弱目标混合积累算法。采用广义二分法对长积累时间内回波信号进行有效非均匀子孔径划分, 以保证单个子孔径内目标信号能量集中至同一距离单元。使用分数阶傅里叶变换校正子孔径内目标能量跨多普勒单元徙动, 实现子孔径内目标信号相参积累。利用动态规划算法完成子孔径间目标信号的非相参积累。仿真实验表明, 所提方法可以在长时间积累条件下对高机动微弱目标信号能量进行有效积累, 并通过对比实验验证了该方法的可行性。