Wavenumber Domain 2-D Separable Data Reformatting Algorithm for High Squint Spotlight SAR

In the case of high squint spotlight synthetic aperture radar (SAR), if a fixed receive-window is used, the signal is distorted in time domain and frequency domain, leading to a significant amount of redundant data. To improve sampling efficiency, this paper adopts a sliding receive-window for signal sampling. However, using a sliding receive-window introduces 2-D coupling, necessitating 2-D interpolation for decoupling. To achieve efficient and accurate decoupling, this paper proposes a wavenumber domain 2-D separable data reformatting algorithm, which simplifies the 2-D interpolation into two separable 1-D interpolations. The new algorithm proposed in this paper can not only solve the problem of low sampling efficiency in the frequency domain caused by the distortion of the 2-D spectrum in high squint mode, but also improve the processing efficiency of eliminating the 2-D coupling in sliding receive-window mode. The effectiveness of the proposed algorithm is verified by point target simulations and real data processing.