含云大气单次散射参量极大相关k分布优选算法  

Maximum Correlated k-Distribution Optimal Algorithm for Single-Scattering Parameters in Cloudy Atmospheres

作　　者：张寅[1] 张少帅 颜灏 范亦唯 朱桂熠 闫钧华[1] Zhang Yin;Zhang Shaoshuai;Yan Hao;Fan Yiwei;Zhu Guiyi;Yan Junhua(Key Laboratory of Space Photoelectric Detection and Perception,Ministry of Industry and Information Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,Jiangsu,China)

机构地区：[1]南京航空航天大学空间光电探测与感知工业和信息化部重点实验室,江苏南京210016

出　　处：《光学学报》2023年第18期212-224,共13页Acta Optica Sinica

基　　金：国防科技基础加强计划(2021-JCJQ-JJ-0834);国家自然科学基金(61705104)

摘　　要：针对高精度遥感应用中含云大气波段辐射传输计算成本较高的问题,提出单次散射参量极大相关k分布优选算法(SSP-MCKD)。通过分析不同环境条件下含云大气消光系数、单次反照率和不对称因子等参量在光谱分布上的相关性,将CKD理论从单一吸收系数扩展至多种光谱参量。根据对单次散射源函数的影响程度,优选各条谱线的极大相关光谱参量并进行分组重排,在组间和组内求解平均等效参量和求积权重。实验结果表明:与△logk算法和云层属性参数化的相关k分布算法相比,SSP-MCKD适用于吸收、半吸收和透过等各类波段,收敛速度最快;在不同高度云层场景中,辐射亮度平均误差低于2%;在不同类型云层场景中,辐射亮度平均误差低于6%。SSP-MCKD在适用性、稳定性及计算精度方面均具有明显优势。Objective Clouds have a significant influence on radiation propagation in atmospheres.In atmospheric remote sensing,band radiative transfer(BRT)models in cloudy atmospheres are crucial and are widely used in climate change,environmental monitoring,weather forecasting,and other research fields.Although the line-by-line(LBL)model is widely acknowledged as the most accurate BRT calculation method,its widespread usage is constrained by its high cost.Recently,correlated k-distribution(CKD)methods have progressed significantly and have emerged as the most promising alternatives in BRT calculations.They provide a better balance of accuracy and efficiency compared to other methods.However,most CKD methods tend to optimize quadrature parameters based on spectral distributions of absorption coefficients in clear atmospheres and use band-averaged cloud optical properties(COPs),ignoring the influence of COP changing with wavenumber.When COPs vary greatly in the wavenumber space,such treatment will cause significant errors.This paper proposes a CKD method suitable for BRT calculation in cloudy atmospheres that takes into account the effect of spectral parameters other than absorption coefficient on radiation.Methods Given the high cost of band radiative transfer calculations for cloudy atmospheres in remote sensing applications,a maximum correlated k-distribution optimal algorithm for single-scattering parameters(SSP-MCKD)is proposed.First,the CKD theory is extended to multiple spectral parameters for cloudy atmospheres,such as single albedos,asymmetry factors,etc.,after analyzing the correlation of their spectral distributions under different environmental conditions.Further,based on the influence of spectral parameters on the single-scattering source function,the maximum correlated parameter of each spectral line is confirmed.A maximum correlation parameter group is formed by spectral lines with the same maximum correlated parameter.Based on the proportion of spectral lines within groups,the quadrature intervals are divided

关 键 词：遥感 含云大气 波段辐射传输 相关k分布 单次散射源函数 极大相关参量 

分 类 号：O436.2[机械工程—光学工程]