Space Target Detection Based on DBF and GRFT for Ground-Based Distributed Radar

Ground-based distributed radar is a potential technique for space target detection. However, in the case of a low signal-to-noise ratio (SNR), it is difficult to achieve long-term integration due to the limited ephemeris guidance accuracy and complex motion model. To solve this problem, a space target detection algorithm based on digital beamforming (DBF) and generalized radon-Fourier transform (GRFT) is proposed in this letter. To avoid the gain loss caused by ephemeris errors, small-scale beam-searching is conducted through the DBF technique, which also enables the measurement of target angle and even angular velocity. Besides, transforming the problem of energy accumulation into parameterized model matching, the GRFT process can achieve long-term integration effectively in the case of complex motion models. The effectiveness of the algorithm is verified via real data experiments based on a ground-based distributed radar. By showing an effective 30-s integration and a computational efficiency improvement of 40%, the validation of the proposed algorithm has been proved.