FY-3D MERSI-Ⅱ反射太阳波段长期响应衰减估计及订正方法  

Estimation and Correction Method of Long-Term Radiometric Degradation of FY-3D/MERSI-ⅡReflective Solar Bands

作　　者：王玲 胡秀清[1,2,3] 张北 徐寒列[1,2,3] 何兴伟 漆成莉 张晓涵 司一丹 徐娜[1,2,3] 陈林 WANG Ling;HU Xiu-qing;ZHANG Bei;XU Han-lie;HE Xing-wei;QI Cheng-li;ZHANG Xiao-han;SI Yi-dan;XU Na;CHEN Lin(National Satellite Meteorological Center(National Center for Space Weather),China Meteorological Administration,Beijing 100081,China;Innovation Center for FengYun Meteorological Satellite(FYSIC),China Meteorological Administration,Beijing 100081,China;Key Laboratory of Radiometric Calibration and Validation for Environme ntal Satellites,China Meteorological Administration,Beijing 100081,China)

机构地区：[1]国家卫星气象中心(国家空间天气监测预警中心),中国气象局,北京100081 [2]许健民气象卫星创新中心,中国气象局,北京100081 [3]中国气象局遥感卫星辐射测量和定标重点开放实验室,中国气象局,北京100081

出　　处：《光谱学与光谱分析》2024年第7期2045-2055,共11页Spectroscopy and Spectral Analysis

基　　金：国家重点研发计划项目(2022YFB3903200,2022YFB3903201,2022YFB3902901)资助。

摘　　要：遥感仪器的长期辐射响应衰减估计与订正是提高卫星遥感数据稳定性和准确性的关键。利用MERSI-Ⅱ在沙漠和DCC稳定目标上空的长时间观测数据,建立仪器辐射响应与时间的函数关系模型,并通过逆方差加权平均方法融合两种稳定目标的结果,获取仪器辐射响应退化量和辐射定标系数的序列估计。辐射响应衰减跟踪监测结果表明,MERSI-Ⅱ自在轨开始业务运行到2022年9月,波长小于500 nm的3个蓝光波段(通道1,通道8—9)和波长大于1000 nm的4个近红外-短波红外波段(通道5—7,通道19)存在明显衰减,年衰减率为1.47%~4.32%。L1级产品精度检验也发现,7个明显衰减通道的业务定标偏差均超过±5%,其中通道5和8偏差最大,约为-20%。应用本研究获取的辐射定标系数序列后,L1产品辐射定标精度随时间变化平稳,定标偏差维持在±3%以内,同时L2级产品精度也明显提升,表明了该研究建立的辐射衰减估计与订正方法的有效性。The estimation and correction of long-term radiometric degradation in remote sensing instruments are crucial for improving the stability and accuracy of satellite remote sensing applications.This study used long-term observation data of FY-3D/MERSI-Ⅱ over stable targets in deserts and DCC(Deep Convective Clouds)to establish a function relationship model between instrument radiation response and time.We further obtained estimates of the best radiometric response degradation and radiometric calibration coefficient using the inverse variance weighted average method to integrate the results of two stable targets.The radiometric degradation tracking resultsshow that from the beginning of FY-3D/MERSI-Ⅱ's in-orbit to September 2022,there is significant degradation in three blue light bands(band 1,bands 8—9 with wavelengths less than 500 nm)and four near-infrared-shortwave infrared bands(bands 5—7,band 19 with wavelengths greater than 1000 nm),with annual degradation rates ranging from 1.47%to 4.32%.Precision testing of L1 products reveals that the operational calibration bias of seven significantly degraded Bands exceeded±5%,with bands 5 and 8 having the most significant bias,about-20%.After applying the radiometric calibration coefficient sequence obtained in this study,the radiometric calibration precision remains stable over time,with calibration bias maintained within±3%.The accuracy validation results of L2 products show that the use of newly obtained calibration coefficients has improved product accuracy compared to operational products.These results indicate the effectiveness of the radiometric calibration method established in this study.

关 键 词：反射太阳波段 辐射响应衰减 MERSI-Ⅱ FY-3D 稳定目标 

分 类 号：TP722.4[自动化与计算机技术—检测技术与自动化装置]