超光谱大气CO2监测仪光谱定标误差修正

Error Correction of Spectral Calibration for Hyper-Spectral Atmosphere CO_2 Monitoring Instrument

超光谱大气CO_2探测需对遥感器进行精确表征及定标,其中光谱定标工作最为基础。针对传统实验室定标方法获取的波长定标系数不确定度高等特点,开展基于气体吸收法原理的光谱定标误差修正研究,该方法与仪器使用状态一致,提高了定标系数实用性。首先利用辐射传输进行了理论光谱及误差因素模拟计算,并基于大气环境模拟定标仓开展了大气XO_2吸收光谱测量实验,最后采用LM算法进行光谱误差修正迭代优化。光谱定标误差修正结果表明:光谱偏差均值由修正前的0.03 cm^(-1)下降到修正后0.008 cm^(-1),且系统性与突变性误差得以剔除,大大提高了地面光谱定标精度,为后续温室气体反演奠定了基础。

The detection of hyper-spectral atmosphere CO2 needs remote sensor to be characterized and calibrated precisely while spectral calibration is the most basic work .The high uncertainty of wavelength calibration coefficient is a big problem as to the traditional laboratory calibration methods .In order to solve this problem ,the research of error correction of spectral calibration based on gas absorption principle is carried out .The method is in accordance with the using conditions of instrument and it im-proves the practicability of the calibration coefficient .First ,theoretical spectrum and error components are simulated by using radiative transfer .Then ,the experiment of atmosphere CO2 absorption spectrum measurement is performed based on the atmos-phere environmental simulation calibration house .Last ,spectral error is corrected and optimized with LM algorithm .The result of spectral calibration of error correction shows that the mean value of spectral error deviation decreases from 0.03 cm -1 before correction to 0.008 cm-1 after correction ,and systematic and mutable errors are removed .The spectral calibration precision on the ground is improved significantly ,which lays the foundation for the subsequent greenhouse gas retrieval .