官莉, 李晟祺. 星载微波成像仪无线电频率干扰软件识别算法综述[J]. 电波科学学报, 2020, 35(2): 280-291. doi: 10.13443/j.cjors.2018121201
      引用本文: 官莉, 李晟祺. 星载微波成像仪无线电频率干扰软件识别算法综述[J]. 电波科学学报, 2020, 35(2): 280-291. doi: 10.13443/j.cjors.2018121201
      GUAN Li, LI Shengqi. Review on software identification methods for radio frequency interference of spaceborne microwave radiometer[J]. CHINESE JOURNAL OF RADIO SCIENCE, 2020, 35(2): 280-291. doi: 10.13443/j.cjors.2018121201
      Citation: GUAN Li, LI Shengqi. Review on software identification methods for radio frequency interference of spaceborne microwave radiometer[J]. CHINESE JOURNAL OF RADIO SCIENCE, 2020, 35(2): 280-291. doi: 10.13443/j.cjors.2018121201

      星载微波成像仪无线电频率干扰软件识别算法综述

      Review on software identification methods for radio frequency interference of spaceborne microwave radiometer

      • 摘要: 气象卫星仪器使用的光谱中只有微波观测可以部分穿过云区,常被用来反演地表温度、海表温度等重要的地表参数.近年来随着地面通信等主动微波技术的发展和商业服务中对微波波段的使用日益增多,被动接收来自地球-大气系统辐射的星载微波仪器观测越来越受到主动微波发射的影响,尤其是在低频波段遥感探测量中增加了不可预测的噪声,造成观测亮度温度相比视场内来自自然大气和地表发射、散射辐射而言异常偏大,进而使反演的地表参数和资料同化的分析场具有较大偏差.卫星微波接收的来自地气系统的被动热辐射与主动传感器发射的信号相混合,被称为无线电频率干扰(radio-frequency interference,RFI);星载微波辐射计接收的辐射测量受地表反射的静止电视或通信卫星下行信号干扰,称之为电视频率干扰(TV frequency interference,TFI).如果不正确识别和去除污染资料,将大大降低星载被动微波仪器的科学价值.本文总结了谱差法、主成分分析法、平均值标准差法、模拟差法等几种常用的RFI软件识别算法,以及谱差比值法、SE法等几种较新的识别算法,并对各种算法的适用范围及优缺点进行了评述.同时详细介绍了源自反射的静止电视或通信卫星下行信号对星载微波观测造成污染的特征及识别、订正方法.

         

        Abstract: Compared to visible and infrared spectrum used by meteorological satellite instruments, microwave remote sensing is not affected easily by atmosphere because of its strong penetration capability of the cloud, rain and atmosphere, and also its all weather and all day monitoring capability.Moreover, microwave sensors are very sensitive to changes of vegetation characteristics, soil moisture and snow parameters.So microwave measurements have been widely used in land and sea surface parameters monitoring and retrieving.However, in recent years, due to the increasing conflict between scientific and commercial users of the radio spectrum, these lower frequency bands observations of spaceborne microwave imagers which recieves passively earth-atmosphere system thermal radiations are more and more affected by the signals from lower frequency active microwave transmitters. Man-made RFI originates from transmitters on surface, airborne, and spaceborne platforms and contaminates remote measurements of the Earth's scattering and emission by adding spurious noise of unpredictable characteristics, resulting in too higher brightness temperatures than nature surface within the field of view. Such a phenomenon of satellite measured passive microwave thermal emission being mixed with the signals from the active sensors is referred to as radio frequency interference (RFI). The interferences of the radiance measurements from the meteorological satellite radiometric instruments with TV signals reflected off the ocean surface are known as television frequency interference (TFI). If not properly identified and rejected, this RFI or TFI contamination problem would introduce errors in the product retrieval and data assimilation, and could significantly reduce the science value of existing and future passive microwave missions.Several common software RFI identifying algorithms for spaceborne microwave radiometer are systematically reviewed in this paper, such as spectral difference method, mean and standard deviation method, model difference method, principal component analysis method, et al., as well as some new methods, standard error of estimate method, ratio of spectral differences. The main advantages and limitations along with the application scope of each method are also discussed.At the same time, the TFI distribution characteristics, as well as detection and correction method to interference from reflected stationary communication and television satellite downlink signal are introduced in detail.

         

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