A joint spatial-temporal coherent integration detection method for space-borne distributed radar system

This study focuses on the coherent integration (CI) of space-based distributed radar for space high-speed maneuvering targets. The platform space difference and high-speed motion result in the envelope position offset and phase difference of the inter-channel signals. Meanwhile, the high-speed and maneuvering characteristics of the target will lead to the range walk (RW) and doppler walk (DW) in the pulse accumulation in single node, which brings challenges to the detection of space targets. This paper presents a method for spatial-temporal joint coherent integration and parameter estimation based on the time-space range history. Firstly, based on the coupling relationship of spatial and temporal in the range history, we established inter-channel envelope correction and phase compensation function to address the inter-channel echo range and phase difference caused by spatial location differences between nodes. Secondly, we combined inter-channel synthetic compensation with generalized Radon-Fourier transform (GRFT). Thus, target range, angle, velocity, and acceleration parameter estimation are integrated into a unified framework. Finally, joint Spatial-temporal joint CI and parameter estimation for space-borne distributed radar system can be implemented. Simulation results demonstrate the effectiveness of the proposed method.