碳卫星高光谱CO2探测仪发射前光谱定标

摘要

In order to realize spectral calibration for TanSat''s hyperspectral Carbon Dioxide Spectrometer (CDS), a calibration system was established and relevant methodology such as design of the system, data acquisition and algorithms of data processing and etc was investigated.Based on the sounding principle, CDS''s spectral requirements were presented.Design of calibration system and the adopted equipments was described.Then after the scheme of Orbiting Carbon Observatory''s spectral calibration was compared, the modified methods such as automatic data acquisition, rotatable integrating sphere, power and dark calibration was analyzed.Finally, the methods of data processing were described as well.Experimental results indicate that the ILS concentration radios of CDS are more than 0.80, 0.81, 0.78 respectively and the intervals of FWHM are 0.039 2-0.042 4 nm, 0.123-0.128 nm, 0.157-0.168 nm respectively.The intervals of spectral sampling are 2.12-2.95, 1.97-2.27, 1.92-2.26 respectively.The comparison of on-orbit solar spectra indicate that the difference of central wavelength are less than 0.001 3, 0.058, 0.065 nm respectively.It can satisfy the system requirements of CDS.%为了完成碳卫星高光谱CO2探测仪的发射前光谱定标,建立了光谱定标系统,并对定标系统设计、所采用的自动化数据采集和数据处理算法等进行了研究.根据CO2探测仪的探测原理介绍了载荷的光谱性能要求,描述了定标系统的设计与所采用的仪器设备,说明了采用自动化数据采集、旋转积分球、功率校正与暗背景校正等改进的定标方法.最后,介绍了光谱定标的数据处理方法.发射前定标结果表明:载荷三个波段的ILS能量集中度分别大于0.80,0.81和0.78;FWHM分别为0.039 2~0.042 4 nm,0.123~0.128 nm和0.157~0.168 nm;光谱采样率区间分别为2.12~2.95、1.97~2.27和1.92~2.26.对发射后实测太阳夫朗禾费光谱进行了评估,结果表明:中心波长偏差小于0.0013,0.058和0.065 nm.CO2探测仪整体的光谱性能指标能够达到系统设计要求.