步进正负调频信号实现MIMO SAR距离高分辨  

Generation of High Range Resolution in MIMO SAR via Stepped Frequency Up-and-Down Chirp Signal

作　　者：马喜乐[1] 董臻[1] 孙造宇[1] 

机构地区：[1]国防科学技术大学电子科学与工程学院,湖南长沙410073

出　　处：《信号处理》2011年第5期781-785,共5页Journal of Signal Processing

摘　　要：带宽合成技术通过多子带步进调频信号的数据融合实现距离向超高分辨。单相位中心顺序收发的模式对系统PRF要求较高,在星载条件下不利于实现高分大测绘带成像。文章对基于多发多收(MIMO)SAR系统的子带并发体制进行研究,详细阐述该体制下子带信号合成的方法,指出带宽合成前必须对相位中心的位置差异进行校正,针对子带串扰带来的虚像问题,首先对其出现机理进行详细分析,最后提出应用步进正负调频信号的方法,在距离压缩后进行子带合成,在实现距离高分辨的同时进一步抑制虚像峰值,仿真结果验证了方法的有效性。Synthetic bandwidth technology realizes super range resolution by fusing multi-band stepped chirp signal.The mode that transmitting and receiving sub-band signal in consequence with single phase center imposes strict request on pulse repetition frequency （PRF）,which means that this mode is not suit for high resolution wide swath imaging of space-born SAR.This thesis focuses on multiple-input multiple-output（MIMO）SAR based concurrent-sub-band system,interprets the principal of signal processing, pointes out the indispensability of correction of azimuth positions.Because of the overlap between neighboring sub-band,unwanted virtual image is unavoidable.The mechanism of the virtual image is interpreted in detail,stepped frequency up-and-down chirp signal based approach is put forward to suppress the peak level of the unwanted profile,the validity of the approach is demonstrated by simulation results.

关 键 词：合成孔径雷达 多发多收 带宽合成 虚像抑制 步进正负调频 

分 类 号：TN95[电子电信—信号与信息处理]