基于ERA5海洋再分析资料的卫星热红外辐射定标方法精度评估  

Accuracy evaluation of the satellite thermal infrared radiometriccalibration method based on ERA5 ocean re-analysis data

作　　者：薛亚楠 马灵玲 王宁 李坤 王新鸿 韩启金[3] 钱永刚 李大成[4] XUE Yanan;MA Lingling;WANG Ning;LI Kun;WANG Xinhong;HAN Qijin;QIAN Yonggang;LI Dacheng(Key Laboratory of Quantitative Remote Sensing Information Technology,Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100094,China;School of Optoelectronics,University of Chinese Academy of Sciences,Beijing 100049,China;China Centre for Resources Satellite Date and Application,Beijing 100094,China;Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]中国科学院空天信息创新研究院,中国科学院定量遥感信息技术重点实验室,北京100094 [2]中国科学院大学光电学院,北京100049 [3]中国资源卫星应用中心,北京100094 [4]太原理工大学,太原030024

出　　处：《遥感学报》2023年第5期1150-1165,共16页NATIONAL REMOTE SENSING BULLETIN

基　　金：国家重点研发计划(编号:2018YFB0504900,2018YFB050490304)~。

摘　　要：卫星红外载荷辐射定标是定量化应用的重要前提,选择合适的辐射定标参考是实现卫星传感器高频次、高精度定标,进而维持全生命周期观测稳定性的保障。再分析资料能够提供全球覆盖、一定空间和时间分辨率的地表及大气数据,已在气候应用中展现了重要价值,其作为辐射定标参考的适用性值得研究。本文以欧洲中期天气预报中心ERA5再分析资料为研究对象,首先利用Argo浮标观测海表温度(SST)和Terra-MODIS L2级SST日产品,对ERA5数据集的海洋表皮温度参数(SSTskin)进行验证;其次利用MODIS观测星上亮温值,对使用ERA5 SSTskin和大气廓线数据模拟得到星上亮温值进行验证。结果表明,ERA5 SSTskin与Argo SST的平均偏差在-0.31 K以内,与MODIS SST产品的平均偏差在-0.38 K以内,且与Argo SST的偏差在时间和空间上更为稳定;辐射传输计算结果显示,与星上观测亮温的平均偏差也在-0.38 K以内,且偏差随时间和纬度变化波动较小。最后,本文还探究了风速、大气水汽柱总量、海浪平均高度等气象影响因素与海表温度偏差和星上亮温偏差的相关性,整体看来,在6—16 m/s中等风速,低于7.0 g/cm2水汽柱总量以及0.6—3 m海浪平均高度的条件下,海表温度偏差以及星上亮温偏差较低。研究结果可为再分析资料用于不依赖实测数据的卫星红外载荷绝对辐射定标提供有效支撑。Thermal infrared radiometric calibration of satellite sensors is an important prerequisite of quantitative remote sensing.An appropriate radiometric calibration source ensures high-frequency,high-precision calibration of satellite sensors and guarantees observation stability during the on-orbit stage.Re-analysis data provide global surface and atmospheric data with a fixed resolution,and they are crucial to climate applications.The feasibility of using re-analysis data as a reference source for radiometric calibration is worthy of being studied.In this study,the ERA5 re-analysis data of the European Center for Medium-range Weather Forecasting were used.Argo buoy Sea Surface Temperature(SST)and Terra-MODIS L2 SST daily products were employed to verify the sea surface skin temperature(SSTskin)of ERA5.The MODIS-observed brightness temperature was used to verify the Top Of Atmosphere(TOA)simulation with the support of ERA5 SSTskin and atmospheric profile data.Results showed that the Mean Bias Error(MBE)between ERA5 SSTskin and Argo SST was-0.31 K,and the MBE between ERA5 SSTskin and MODIS SST was-0.38 K.The former temperature difference was more stable than the latter.The root mean square error between the simulated TOA brightness temperatures and the MODIS observations was also-0.38 K.In addition,some meteorological factors,such as wind speed,total column water vapor,and ocean wave height,were used to analyze the correlation between the SSTskin differences and TOA brightness temperature.Overall,under the conditions of medium wind speed of 6—16 m/s,total column water vapor of less than 7.0 g/cm2,and ocean wave height of 0.6—3 m,the difference between SSTskin and TOA brightness temperature was small.These findings can provide an accurate basis for the use of re-analysis data as a reference source in thermal infrared radiometric calibration.

关 键 词：再分析资料 海表面温度 星上亮温 辐射定标参考 

分 类 号：P2[天文地球—测绘科学与技术]