基于谱延拓的SAR复图像谱分裂目标Doppler解模糊  

Spectrum extension based Doppler ambiguity resolution for SAR split-spectrum targets in complex images

作　　者：夏斌[1] 许稼[1] 彭应宁[1] 

机构地区：[1]清华大学电子工程系,北京100084

出　　处：《清华大学学报（自然科学版）》2011年第3期428-432,共5页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金项目(60971087);部委预研基金(9140A07051208JW0111);航空科学基金(20080158001);航天科技重点创新基金(CASC200904);航天支撑基金(J04-2007047)

摘　　要：合成孔径雷达(SAR)地面目标的径向运动会导致Doppler模糊,将目标Doppler频谱分裂为不同模糊数的2部分,显著增加了目标定位、识别和分类的难度。为实现谱分裂类型目标解模糊,该文基于复图像距离-Doppler(R-D)域的目标包络斜率正比于模糊数的特性,提出一种在谱延拓R-D域作二次距离徙动校正、搜索残留徙动斜率最小值的模糊数估计方法,克服了谱分裂造成的包络不连续性。新方法计算效率高且无需辅助硬件支持。基于机载SAR实测数据的数值实验表明:新方法可有效实现谱分裂目标模糊数估计。The radial motion of a ground target in synthetic aperture radar（SAR） can result in the Doppler ambiguity with the target Doppler spectrum split into two parts with different ambiguity integers,causing difficulties in target location,recognition and classification.An algorithm was developed to resolve the Doppler ambiguity of split-spectrum targets based on the fact that,in the range-Doppler（R-D） domain of the complex SAR image,the slope of the target signal is proportional to its ambiguity integer.A second range cell migration correction（S-RCMC） in the R-D domain after the spectrum extension can estimate the ambiguity integer by searching the minimum residual slope after the S-RCMC,eliminating the influence of the envelope discontinuity.This approach is computationally efficient and has no need for auxiliary hardware support.Numerical tests based on real data demonstrate the effectiveness of the method.

关 键 词：合成孔径雷达 地面运动目标指示 Doppler模糊 谱分裂目标 Doppler谱延拓 

分 类 号：TN957.51[电子电信—信号与信息处理]