偏振氧A带光谱气溶胶垂直剖面反演的信息量分析和灵敏度研究

Information content analysis and sensitivity of retrieval of aerosol vertical profiles using polarimetric oxygen A-band spectra

为评估从偏振氧A带光谱中提取的气溶胶垂直剖面的信息量及提高光谱分辨率对偏振测量的气溶胶垂直剖面信息的影响,采用线性化矢量辐射传输模型(UNL-VRTM),对氧A波段线偏振度(DoLP)星载测量中气溶胶垂直剖面的信息量及不同观测条件和光谱分辨率下DoLP的气溶胶峰高信息量变化的影响因素进行分析。研究结果表明,DoLP所包含的气溶胶峰高的信息比辐射度更多,辐射度的信号自由度(DFS)最高为0.49,而DoLP的DFS为0.76;且随着光谱分辨率的提高,气溶胶峰高信息量增加,对表面反射率、观测几何以及先验误差的依赖大大降低。

In order to evaluate the amount of vertical information on aerosol extinction profiles extracted from the O_(2) A-band polarization spectrum and the influence of improving spectral resolution on aerosol vertical profile information measured by polarization,the Unified Linearized Vector Radiative Transfer Model(UNL-VRTM)is used to analyze the information from satellite measurements of O_(2) A-band degree of linear polarization(DoLP)and the influencing factors of aerosol peak height information of DoLP under different observation conditions and spectral resolution.Simulation results show that DoLP contains more information content for aerosol peak height than radiation intensity,and the maximum degree of freedom of signal(DFS)of radiation intensity is 0.49,while the DFS of DoLP is 0.76.In addition,with the improvement of spectral resolution,the information content of aerosol peak height increases,and the dependence on surface albedo,observation geometry and prior error is greatly reduced.