Two-Stage Coherent Integration for High-Speed Maneuvering Target in Wideband Radar Based on FA/SA-RPIT

High-speed maneuvering targets in wideband radar present severe challenges for coherent integration due to range migration, Doppler frequency migration, and range spread. To address these issues, this article proposes the full-aperture and subaperture range-phase-invariant transforms, which jointly mitigate energy dispersion and enable coherent accumulation across multiple scatterers. The proposed transforms achieve invariance to both the initial range and phase of scatterers, allowing effective envelope and phase alignment. Theoretical analysis and simulations demonstrate an output signal-to-noise ratio gain of at least 10\log ₁₀ K dB as the number of scatterers K increases, while both simulated and measured data confirm the superior performance and practical effectiveness of the proposed methods in wideband radar scenarios.