关键词: 快速后向投影算法, 分布式合成孔径雷达, 一发多收, 波数矢量分解, 频谱递归融合

Abstract:

In the case of forward-looking imaging with single-transmitter-multiple-receiver （STMR）, the elliptic coordinate system involved in the traditional algorithm makes it difficult to maintain the orthogonal decomposition of the wavenumber vector, which exacerbates the irregularity in the shape and range of the wavenumber spectrum to reduce multi-platform image merging performance and the accuracy of motion error estimation. To address this problem, a multi-center polar coordinate system is designed, which ensures the orthogonal decomposition of the wavenumber vector in STMR forward-looking configurations and maintains the regularity of the wavenumber spectrum’s shape and range. The spectrum processing function is redesigned based on the spectrum recursive merging strategy in the fast back projection （FBP） algorithm to accurately and rapidly merge images from different platforms. Simulation results demonstrate that the proposed method requires lower image sampling rates and achieves higher image merging efficiency compared to conventional methods under alias-free spectral conditions. Under ideal sampling conditions, the proposed method also delivers superior image merging accuracy. Simulation experiments validate the effectiveness of the proposed method in enhancing both imaging quality and merging efficiency, providing an effective solution for high-resolution forward-looking imaging in systems.

Key words: fast back projection （BP） algorithm, distributed synthetic aperture radar (DiSAR), single-transmitter-multiple-receiver （STMR）, wave number vector decomposition, recursive spectrum merging