星载痕量气体差分吸收光谱仪1级数据质量评价  

Evaluations of Environmental Trace Gases Monitoring Instrument(EMI)Level 1 Data

作　　者：程良晓 陶金花 周海金 余超 范萌 王雅鹏 王志宝[5] 陈良富 CHENG Liang-xiao;TAO Jin-hua;ZHOU Hai-jin;YU Chao;FAN Meng;WANG Ya-peng;WANG Zhi-bao;CHEN Liang-fu(State Key Laboratory of Remote Sensing Science,Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing Normal University,Beijing 100101,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Environmental Optics and Technology,Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Hefei 230031,China;National Satellite Meteorological Center,China Meteorological Administration,Beijing 100081,China;School of Computer and Information Technology,Northeast Petroleum University,Daqing 163318,China)

机构地区：[1]中国科学院空天信息创新研究院/北京师范大学,遥感科学国家重点实验室,北京100101 [2]中国科学院大学,北京100049 [3]中国科学院安徽光学精密机械研究所,环境光学与技术重点实验室,安徽合肥230031 [4]国家卫星气象中心,北京100081 [5]东北石油大学计算机与信息技术学院,黑龙江大庆163318

出　　处：《光谱学与光谱分析》2021年第12期3881-3886,共6页Spectroscopy and Spectral Analysis

基　　金：国家重点研发计划项目(2017YFB0503901,2018YFC0213901,2018YFC0213904);中国科学院战略先导专项(XDA19010403,XDA19040201);国家自然科学基金项目(41771391);东北石油大学优秀中青年科研创新团队项目(KYCXTD201903)资助。

摘　　要：星载痕量气体差分吸收光谱仪(EMI)是我国第一台用于监测对流层和平流层痕量气体的高光谱分辨率成像光谱仪。为了充分了解载荷的特点,更好地利用1级数据进行痕量气体反演,本研究对EMI实测的辐照度和辐亮度数据进行了综合评价。研究表明EMI紫外2波段(UV2)和可见光1波段(VIS1)的狭缝函数都表现出明显的行依赖性,其随行波动的标准差是OMI和TROPOMI的6倍以上。对不同行采用不同的狭缝函数,可以提高辐照度光谱的定标精度,进而提高痕量气体反演精度。EMI辐照度和辐亮度数据都有波长漂移现象,平均漂移量分别为0.015和0.03 nm,有明显的行依赖性。目前的波长漂移量满足设计指标(0.05 nm)的要求,但在痕量气体反演过程中仍需进行波长精校准。EMI辐照度数据与OMI和TROPOMI同一天测量的辐照度以及参考太阳光谱高度一致(r>0.95),绝对偏差小于4.3%;通过对比在洁净太平洋地区无云像元的平均辐亮度数据发现,EMI与OMI和TROPOMI也有很好的一致性(r>0.93),平均偏差小于13.2%;说明EMI数据辐射定标精度较高。研究表明当前EMI载荷数据质量能够满足痕量气体反演的要求,可为后续国产载荷的研制和数据质量评估方案提供参考。The Environmental trace gases Monitoring Instrument(EMI)is the first high spectral resolution imaging spectrometer in China designed to monitor trace gas in tropospheric and stratospheric.To fully understand the instrument’s characteristics and make better use of the level 1(L1)data,comprehensive evaluations of irradiance and radiance data measured by the EMI instrument were carried out in this study.For both ultraviolet-2 and visible-1 bands,the slit function change drastically as a function of detectors in the across-track direction of charge-coupled device(CCD),which is more than 6 times larger than that of TROP(OMI).The use of different slit functions according to the row can improve the calibration accuracy.Small wavelength shifts were found in both irradiance and radiance data with an average value of 0.015 and 0.03 nm,respectively.Although they meet the requirement of the design specification(0.05 nm),wavelength calibration is still needed during the trace gas retrieval.EMI irradiance data agree highly(r>0.95)with OMI and TROPOMI and the reference solar spectrum.EMI radiance data also shows a better agreement(r>0.93)with OMI and TROPOMI by averaging the cloud-free pixels over the clean Pacific region.This study demonstrates the good quality of current EMI L1 data for trace gas retrieval,and it provides a reference for the design and data quality evaluation scheme of subsequent instruments.

关 键 词：GF-5 星载痕量气体差分吸收光谱仪 定标 狭缝函数 数据质量 

分 类 号：O433.4[机械工程—光学工程]