GNSS极化测量降雨正演模拟与实验对比  

Forward Simulation and Comparative Experiment Analysis of Polarimetric GNSS Radio Occultations Detecting Rainfall Events

作　　者：苏豆豆 白伟华 杜起飞[1,3,4,5] 孙越强 谭广远[1,2,3,4,5] SU Doudou;BAI Weihua;DU Qifei;SUN Yueqiang;TAN Guangyuan(National Space Science Center,Chinese Academy of Sciences,Beijing 100190;University of Chinese Academy of Sciences,Beijing 100049;Beijing Key Laboratory of Space Environment Exploration,Beijing 100190;Key Laboratory of Science and Technology on Space Environment Situational Awareness,Chinese Academy of Sciences,Beijing 100190;Joint Laboratory on Occultations for Atmosphere and Climate,Beijing 100190)

机构地区：[1]中国科学院国家空间科学中心,北京100190 [2]中国科学院大学,北京100049 [3]天基空间环境探测北京市重点实验室,北京100190 [4]中国科学院空间环境态势感知技术重点实验室,北京100190 [5]掩星探测与大气气候应用国际联合实验室,北京100190

出　　处：《空间科学学报》2022年第5期961-972,共12页Chinese Journal of Space Science

摘　　要：研究证明,全球导航卫星系统(GNSS)极化无线电掩星(PRO)技术可以用于探测降雨。利用GPM DPR降雨率数据与PAZ卫星极化相移观测数据匹配,筛选出代表性降雨事件。通过选用TB等7种雨滴形状和MP等5种雨滴谱模型,采用T矩阵法对各事件进行正演,并分析PAZ极化相移的线性校正值、天线相位校正值与正演模拟值之间的关系。对比分析得出线性校正值、相位校正值与模拟值的相关系数分别为0.9994和0.9933,均方根差分别为0.3429和1.2765。模拟值与实测值之间高度相关,且更接近线性校正值。进一步的研究表明,模拟降雨率在1 mm·h^(–1)以下的事件时,雨滴谱采用MP或JD分布,雨滴形状采用SC或PB的模拟精度更高;降雨率在1 mm·h^(–1)以上的事件,雨滴谱采用MP或SS分布,雨滴形状采用TB的模拟结果最优。Studies have proved that the Global Navigation Satellite System(GNSS)Polarimetric Radio Occultation(PRO)technology has the possibility of detecting rainfall.This study uses GPM DPR products as rainfall rate data to collocate with the latest PAZ satellite observation data,and selects representative rainfall events with a wide range of rainfall and matching with RO events.By selecting 7 raindrop shapes such as TB,and 5 raindrop size distribution models such as MP,the T-matrix method is used to simulate these rainfall events.The Pearson correlation coefficient,root mean square error,and other parameters between the simulated polarimetric phase shift and the observation data calibrated using linear trend,or the observation data calibrated using antenna pattern are calculated respectively.The Pearson correlation coefficients between the simulated value and the calibrated value using linear trend,or the calibrated value using antenna pattern are 0.9994 and 0.9933,respectively.The root mean square error between the simulated value and the calibrated value using linear trend,or the calibrated value using antenna pattern are 0.3429 and 1.2765,respectively.The comparative analysis results show that there is a high correlation between the simulated value and the polarimetric phase shift measured by PAZ and the simulated results are closer to the polarimetric phase shift calibrated using linear trend.The results show that adopting MP or JD as the raindrop size distribution model and SC or PB as the raindrop shape can get higher accuracy when simulating events with a small rainfall rate(below 1 mm·h^(–1)).For events with high rainfall rates(above 1 mm·h^(–1)),selecting the MP or SS raindrop size distribution model and the TB raindrop shape can simulate the best results.

关 键 词：极化相移 极化无线电掩星 降雨 正演 

分 类 号：P412[天文地球—大气科学及气象学]