Abstract: The back projection algorithm using local approximation（LBP, Local Back Projection） is not suitable for imaging in Geosynchronous Synthetic Aperture Radar（GEO SAR） for the sake of high orbit and extremely long synthetic aperture. Combined with the traditional LBP algorithm principle, the GEO SAR phase error model based on LBP is constructed, and the LBP imaging processing method suitable for GEO SAR is proposed. The imaging results have the same quality with traditional BP algorithm, the computational efficiency is increased by 75 times.

Key words: Geosynchronous Synthetic Aperture Radar（GEO SAR）, Local Back Projection（LBP）, phase compensation

摘要： 地球同步轨道合成孔径雷达（Geosynchronous Synthetic Aperture Radar，GEO SAR）轨道高，合成孔径长，采用局部近似处理的后向投影算法（Local Back Projection，LBP）不再适用。结合传统LBP算法原理，构建了基于LBP的GEO SAR相位误差模型，提出了适用于GEO SAR的LBP成像处理方法。仿真结果表明改进后的LBP算法在保证成像质量与传统BP算法基本相近的同时，将计算效率提升了75倍。

关键词: 地球同步轨道合成孔径雷达, 局部后向投影, 相位补偿