Effects of spectral sampling rate and range of CO_2 absorption bands on XCO_2 retrieval from TanSat hyperspectral spectrometer  

作　　者：Yi Liu Zhaonan Cai Dongxu Yang Yuquan Zheng Minzheng Duan Daren L 

机构地区：[1]Key Laboratory of Middle Atmosphere and Global Environment Observation,Institute of Atmospheric Physics,Chinese Academy of Sciences [2]Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences

出　　处：《Chinese Science Bulletin》2014年第14期1485-1491,共7页

基　　金：supported by the Strategic Priority Research Program-Climate Change: Carbon Budget and Relevant Issues (XDA05040200);the National High-tech R&D Program of China (2011AA12A104);the National Natural Science Foundation of China (41205018)

摘　　要：The spectral sampling rate and range of CO2absorption bands are critical for the optimal design of hyperspectral instrument for CO2observation satellite.Undersampling of spectra in space-based spectrometer significantly contaminates signals measured in the CO21.61 lm-band.The CO2dry-air column(XCO2)error due to spectral undersampling can be up to*1 ppm,which is the target precision of the Chinese Carbon Satellite(TanSat)for a single sounding.Undersampling error depends on surface albedo,solar zenith angle,and scattering properties in the atmosphere.The spectral sampling rate is recommended to be greater than 2.0 pixels per full width at half maximum to avoid undersampling.Reduction of spectral resolution and the use of narrower spectral regions can improve spectral sampling with little changes in CO2retrieval sensitivity without losing much information.The full-band approach provides direct constraints on the wavelength-dependent surface albedo and particle scattering from the measurements.To keep a broader band,we recommend reduction of the spectral resolution by a factor of two.The spectral sampling rate and range of CO2 absorption bands are critical for the optimal design of hyperspectral instrument for CO2 observation satellite. Undersampling of spectra in space-based spectrometer significantly contaminates signals measured in the CO2 1.61 ktm-band. The CO2 dry-air column （XCO2） error due to spectral undersampling can be up to ,1 ppm, which is the target precision of the Chinese Carbon Satellite （TanSat） for a single sounding. Undersampling error depends on surface albedo, solar zenith angle, and scattering properties in the atmosphere. The spectral sampling rate is recommended to be greater than 2.0 pixels per full width at half maximum to avoid undersampling. Reduction of spectral resolution and the use of narrower spectral regions can improve spectral sampling with little changes in CO2 retrieval sensitivity without losing much information. The full-band approach provides direct constraints on the wavelength-dependent surface albedo and particle scattering from the measurements. To keep a broader band, we recommend reduction of the spectral resolution by a factor of two.

关 键 词：采样速率 高光谱 CO2 光谱仪 吸收带 检索 地表反照率 光谱分辨率 

分 类 号：TH744.1[机械工程—光学工程]