基于ADTD的FY-4A卫星闪电探测性能分析  

Detection Performance of FY-4A Lightning Mapping Imager Based on ADTD

作　　者：李云 邱实 孙征 刘毅诚 罗小军 石立华 LI Yun;QIU Shi;SUN Zheng;LIU Yicheng;LUO Xiaojun;SHI Lihua(College of Field Engineering,Army Engineering University of PLA,Nanjing 21007,China)

机构地区：[1]陆军工程大学野战工程学院,江苏南京210007

出　　处：《陆军工程大学学报》2024年第1期63-69,共7页Journal of Army Engineering University of PLA

基　　金：国家自然科学基金(42105077,51977219);江苏省自然科学基金(BK20200584)。

摘　　要：为评估风云四号A星(Fengyun-4A,FY-4A)的闪电探测性能,提出了基于星地闪电数据统计特征的匹配方法:选取较大时空窗口,进行星地数据匹配;对匹配数据的时间差和距离差进行概率统计,确定最合适的时空窗口。通过对我国2020年夏季(6—8月)FY-4A和地基闪电定位系统(advanced direction and time-of-arrival detecting system, ADTD)的闪电数据进行统计,确定时间间隔3.4 s,空间经纬度间隔0.6°作为星地数据一致性分析的时空窗口。基于此时空窗口开展了星地闪电数据的对比分析,结果表明,星地数据时间偏差平均值为1.3 s,空间偏差平均值为23.73 km;FY-4A闪电探测效率为19%,FY-4A探测效率具有明显的日变化特征,白天平均探测效率为7%,明显低于夜晚的31.1%,且白天12:00—14:00时探测效率最低,仅为2.3%;FY-4A闪电数据的光辐射强度日变化特征与太阳高度角的变化呈正相关,白天12:00—14:00时光辐射强度最大达到1 391μJ/m2/sr,比夜晚光辐射强度(124μJ/m2/sr)高一个量级,白天只有光辐射较强的闪电才能被FY-4A闪电成像仪(lightning mapping imager, LMI)捕获,进一步解释了白天闪电探测效率低的原因。To evaluate the lightning detection performance of the FY-4A,this paper proposes a matching method based on the statistical characteristics of the satellite-ground lightning data.First,a larger time-space window is selected for satellite-ground data matching.Then,the time deviation and distance deviation of the matched data are statistically analyzed to determine the final suitable time-space window.By statistically analyzing the summer lightning data(from June to August)in 2020 from FY-4A and ground-based advanced direction and time-of-arrival detecting system(ADTD)in China,it is finally determined that the time interval is 3.4 s and the spatial latitude and longitude interval is 0.6°as the time-space window for satellite-ground data consistency analysis.Based on this time-space window,a comparative analysis of satellite-ground lightning data was carried out.The results show that the average time deviation of satellite-ground data is 1.3 s,and the average space deviation is 23.73 km.The detection efficiency of FY-4A lightning is 19%.It is found that the detection efficiency of FY-4A has obvious diurnal characteristics,with the detection efficiency during the day significantly lower than that at night.The average detection efficiency at night is 31.1%,while during the day it is 7%.The detection efficiency is only 2.3%,the lowest from 12:00 to 14:00 during the day.The diurnal variation of the light radiation intensity of the FY-4A lightning data positively correlates with the change in the solar height angle. The light radiation intensity is the highest from 12:00 to 14:00 during the day, reaching 1 391 μJ/m2/sr, which is an order of magni-tude larger than that at night (124 μJ/m2/sr). This shows that only lightning with strong light radiation can be captured by the FY-4A lightning mapping imager (LMI) during the day, which further explains the reason for the low lightning detection efficiency during the day.

关 键 词：闪电成像仪 闪电探测 探测效率 日变化特征 

分 类 号：P427.3[天文地球—大气科学及气象学]