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

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.