FY-3G MWRI-RM低频通道亮温观测中的无线电干扰信号及其日变化  

Diurnal variations of radio-frequency interference signal detected from FY-3G Microwave Radiation Imager-Rainfall Mission

作　　者：史震源 邹晓蕾[1] SHI Zhenyuan;ZOU Xiaolei(Joint Center of Data Assimilation for Research and Application,Nanjing University of Information Science&Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学资料同化研究和应用联合中心,南京210044

出　　处：《气象科学》2024年第4期691-706,共16页Journal of the Meteorological Sciences

基　　金：国家重点研发计划资助项目(2018YFC1507004)。

摘　　要：由于微波辐射计低频通道的非保护性,亮温观测会受到主动传感器的信号污染,被称为无线电频率干扰(Radio-Frequency Interference,RFI)。RFI信号降低了亮温观测资料及其反演产品的准确度。我国近期发射的风云三号G星(FY-3G)搭载了微波成像仪—降水型(Microwave Radiation Imager-Rainfall Mission,MWRI-RM),在10.65~183.00 GHz的频率范围内设有17个通道,对地球大气进行被动遥感探测。在没有RFI影响情况下,不同通道亮温观测具有高度相关性。利用这一特点,采用标准化主成分分析法,可识别FY-3G MWRI-RM亮温观测资料中RFI的发生位置和强度。与风云三号A/B/C/D/星(FY-3A/B/C/D)不同,FY-3G MWRI-RM可以在不同时间观测到地球同一地点。因此,还可以研究RFI是否有日变化特征。结果表明,RFI信号确实存在于MWRI-RM的低频通道10.65 GHz亮温观测资料中,在中国和欧洲都有集中或零散分布区域,并且呈现日变化特征,RFI强度在白天普遍大于夜间。Due to unprotected low-frequency microwave channels,brightness temperature observations are susceptible to signal contamination from active sensors,referred to as Radio-Frequency Interference(RFI).RFI signals reduce the accuracy of brightness temperature observations and their retrieval products.The Fengyun-3G satellite(FY-3G),recently launched by China,is equipped with a Microwave Radiation Imager-Rainfall Mission(MWRI-RM).MWRI-RM has 17 channels located in the frequency range from 10.65 to 183.00 GHz to enable passive remote sensing of Earth s atmosphere.Exploiting high correlations of brightness temperature among channels if no RFI,a normalized principal component analysis method was employed to detect RFI signals in FY-3G MWRI-RM brightness temperature observations.Unlike FY-3A/B/C/D,FY-3G MWRI-RM can observe the same location on Earth at different times,allowing for an investigation of diurnal variations in RFI.Results indicate that RFI signals do exist in MWRI-RM observations of brightness temperature at 10.65 GHz,with concentrated and scattered distributions in both China and Europe.Moreover,RFI signals indeed exhibit a diurnal variation,with higher intensity during daytime than nighttime.

关 键 词：FY-3G微波成像仪—降水型 无线电频率干扰信号识别 无线电频率干扰信号日变化特征 

分 类 号：P407[天文地球—大气科学及气象学]