VHF波段星载SAR系统电离层效应仿真研究  

Ionospheric effects simulation of space-borne VHF-band SAR system

作　　者：姚佰栋 时晶晶[2] 盛磊 赵宁[1] 葛家龙[1] YAO Baidong;SHI Jingjing;SHENG Lei;ZHAO Ning;GE Jialong(No.38 Research Institute,China Electronic Technology Group Corporation,Hefei 230088,China;Hefei Normal University,Hefei 230601,China)

机构地区：[1]中国电子科技集团有限公司第38研究所,合肥230088 [2]合肥师范学院,合肥230601

出　　处：《空军预警学院学报》2020年第2期84-87,共4页Journal of Air Force Early Warning Academy

基　　金：科技部国际合作专项项目(2015DFA10270)。

摘　　要：为研究VHF波段星载合成孔径雷达(SAR)系统,分析了雷达中心频率、信号带宽、电离层总电子含量(TEC)以及闪烁强度等因素对于VHF波段星载SAR成像的影响,并进行了仿真研究.仿真结果表明,在空间电离层中传播时,VHF波段星载SAR的距离向分辨率与雷达中心频率、信号带宽以及传播路径上的电离层TEC大小密切相关,同时由于时延的影响,还会导致SAR距离向图像发生移位,造成定位精度下降;方位向分辨率受闪烁效应影响严重,当处于弱闪烁或中等闪烁时,旁瓣抬升明显,且产生微小的移位,当处于强闪烁时,方位向分辨率明显降低,甚至无法成像.In order to study space-borne synthetic aperture radar(SAR)in VHF-band,this paper analyzes the effects of radar center frequency,signal bandwidth,ionospheric total electron content(TEC)and scintillation intensity and other factors on space-borne VHF-band SAR imaging.And the paper also makes corresponding simulation studies.The simulation results show that when the electromagnetic waves are propagating through the spatial ionosphere,the range-direction resolution of VHF-band space-borne SAR is closely related to the radar center frequency,signal bandwidth and ionospheric TEC in the propagation path,and at the same time,due to the influence of time delay,offset occurs to the range-direction SAR image,resulting in the decrease of positioning accuracy,and that the azimuth resolution is seriously affected by the ionospheric scintillation effect:in the case of weak or medium scintillation,the side lobe is uplifted obviously and causes slight offset,while in time of strong scintillation,azimuth resolution is significantly reduced,and even imaging is not possible.

关 键 词：电离层 VHF波段 星载合成孔径雷达 分辨率 电离层总电子含量 

分 类 号：TN959[电子电信—信号与信息处理]