2024/01/01 by Suqi Li, Yihan Wang, Bailu Wang +3
Computer Science · #Advanced Image Processing Techniques #Digital Filter Design and Implementation #Image and Signal Denoising Methods
paper · doi:10.1109/tsp.2024.3411161
openalex publication_date 2024/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
Long Time Coherent Integration (LTCI) is an effective method for weak target detection, since it can accumulate target energy through long time observation, thus improving the target output signal-to-noise ratio (SNR). However, for a moving target, defocusing can occur due to range migration (RM) and Doppler frequency migration (DFM). To address this issue, RM and DFM corrections are required in order to achieve a well-focused image for the subsequent detection. Since RM and DFM are induced by the same motion parameters, existing approaches such as the generalized Radon-Fourier transform (GRFT) or the keystone transform (KT)-matching filter process (MFP) adopt the same search space for the motion parameters in order to eliminate both effects, thus leading to large redundancy in computation. To this end, this paper first proposes a dual-scale decomposition of the target motion parameters, consisting of well designed coarse and fine motion parameters. Then, utilizing this decomposition, the joint correction of the RM and DFM effects is decoupled into a cascade procedure, first RM correction on the coarse search space and then DFM correction on the fine search spaces. As such, step size of the search space can be tailored to RM and DFM corrections, respectively, thus avoiding large redundant computation effectively. The resulting algorithms are calleddual-scale GRFT (DS-GRFT)ordual-scale KT-MFP (DS-KT-MFP)which provide comparable performance while achieving significant improvement in computational efficiency compared to standard GRFT (KT-MFP). Simulation experiments verify their effectiveness and efficiency.