大气与环境光学学报 ›› 2021, Vol. 16 ›› Issue (3): 177-185.

• “高分五号卫星大气数据反演”专辑 • 上一篇    下一篇

星载EMI在轨光谱定标方法研究


王歆远1;2, 司福祺1∗, 赵敏杰1, 周海金1, 江 宇1, 汪世美1   


  1. 1 中国科学院合肥物质科学研究院安徽光学精密机械研究所, 中国科学院环境光学与技术重点实验室, 安徽 合肥 230031; 2 中国科学技术大学, 安徽 合肥 230036
  • 收稿日期:2020-10-27 修回日期:2021-01-20 出版日期:2021-05-28 发布日期:2021-05-28
  • 通讯作者: E-mail: sifuqi@aiofm.ac.cn E-mail:sifuqi@aiofm.ac.cn
  • 作者简介:王歆远 (1996 - ), 安徽铜陵人, 硕士研究生, 主要从事星载成像光谱仪光谱定标方面的研究。 E-mail: yyqian@aiofm.ac.cn
  • 基金资助:
    Supported by National Natural Science Foundation Youth Science Foundation Project (国家自然科学基金青年科学基金项目, 41705016)

On-Orbit Spectrum Calibration of Spaceborne EMI

WANG Xinyuan1;2, SI Fuqi1∗, ZHAO Minjie1, ZHOU Haijin1, JIANG Yu1, WANG Shimei1   

  1. 1 Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China; 2 University of Science and Technology of China, Hefei 230036, China
  • Received:2020-10-27 Revised:2021-01-20 Published:2021-05-28 Online:2021-05-28
  • Supported by:
    Supported by National Natural Science Foundation Youth Science Foundation Project

摘要: 于 2018 年 5 月 9 日搭载高分五号卫星发射的大气痕量气体差分吸收光谱仪 (EMI) 为紫外可见波段高分辨率 成像光谱仪。为考察其在轨光谱性能, 首先采用波长寻峰法即以太阳 Fraunhofer 线作为特征峰以快速获取载荷的光谱 范围, 然后采用谱线匹配法获取载荷空间维度的光谱弯曲值, 最后采用光谱拟合法获取光谱分辨率的变化。寻峰法通 过与标准 Fraunhofer 线进行比对找寻特征峰, 得到其标准波长及对应像元, 经二阶多项式拟合可得到像元-波长对应关 系。谱线匹配法通过 Pearson 相关系数法作为判据, 即利用两谱线之间相关系数作为匹配结果的判断条件, 得到测量 谱线与标准谱线间的偏移值, 定标结果满足定标精度高于 0.05 nm 的要求。光谱拟合法通过求解将测量谱与高分辨率 太阳参考谱拟合, 可以分析光谱分辨率变化。对 2019 年 1 月 7 日全天 15 轨数据的分析结果表明, 光谱分辨率在一天 内的变化一致, 其单行标准差不超过 0.01, 因此在之后仪器长时间运作或受到干扰情况下, 利用此方法对其性能衰变 进行分析具有重要意义。

关键词: 大气痕量气体差分吸收光谱仪, 光谱定标, 光谱匹配, 狭缝函数

Abstract: The environmental trace gases monitoring instrument (EMI) launched on the Gaofen-5 satellite on May 9, 2018 is a high-resolution imaging spectrometer in the UV-visible band. In order to investigate its on-orbit spectral performance, the wavelength peak searching method was first adopted, namely, the solar Fraunhofer line was used as the characteristic peak to quickly obtain the spectral range of the load, then the spectral curve value of the load space dimension was obtained by using the spectrum-matching method, and finally the spectral fitting method was used to obtain the change of spectral resolution. By comparing with the standard Fraunhofer, the peak searching method can find the characteristic peak and obtain the standard wavelength of the peak and the corresponding pixel, and then the corresponding relationship between pixel and wavelength can be obtained by second order polynomial fitting. The Pearson correlation coefficient method is used as the criterion for spectral-matching method, that is, the maximum correlation coefficient between two spectral is used as the condition for the optimal matching result, and then the offset value between the measured spectral and the standard spectral is obtained. The calibration result satisfies the requirement that the calibration precision is higher than 0.05nm. The spectral fitting method can analyze the change of spectral resolution by solving and fitting the measured spectrum with the high-resolution solar reference spectrum. The analysis results of the all-day 15-track data on January 7, 2019 show that the change of spectral resolution is consistent within a day, and the single row standard deviation is less than 0.01. Therefore, it is of great significance to analyze the performance decay of the instrument in the case of long-term operation or interference.

Key words: environmental trace gases monitoring instrument, spectral calibration, spectral matching, slit function

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