面向高光谱大气臭氧传感器的多观测几何条件下紫外辐射模拟及对TOMS V8算法臭氧初值估算模型改进与评价  

Radiance Simulation of BUV Hyperspectral Sensor on Multi Angle Observation,and Improvement to Initial Total Ozone Estimating Model of TOMS V8 Total Ozone Algorithm

作　　者：吕春光[1,2] 王维和[3,4] 杨文博 田庆久[1,2] 卢山 陈赟 

机构地区：[1]南京大学国际地球系统科学研究所,江苏南京210023 [2]南京大学江苏省地理信息技术重点实验室,江苏南京210023 [3]中国气象局中国遥感卫星辐射测量和定标重点开放实验室,北京100081 [4]国家卫星气象中心,北京100081 [5]上海航天控制技术研究所,上海200233 [6]上海市空间智能控制技术重点实验室,上海200233

出　　处：《光谱学与光谱分析》2015年第11期2979-2984,共6页Spectroscopy and Spectral Analysis

基　　金：国家科技重大专项(30-Y20A01-9003-12/13);国家重点基础研究发展计划项目(2010CB951503)资助

摘　　要：新型高光谱大气臭氧传感器大多计划搭载地球静止轨道平台,其对大视场范围和时间范围内的臭氧总量提取提出了更高的需求。TOMS V8算法在低轨卫星大气臭氧传感器得到广泛的应用和发展,但其在大观测几何条件下的提取精度不足,因此如何提高TOMS算法在新型传感器上的提取精度是当前亟待解决的问题。利用MODTRAN大气辐射传输模型模拟了晴空场景TOMS算法标准廓线各观测几何条件下的地球紫外后向散射辐射,分析了各观测几何条件下后向散射辐射亮度与臭氧总量拟合模型,并根据模型拟合精度情况,得到了不同观测几何条件下后向散射辐射随臭氧总量的变化关系,提出了改进的臭氧总量初值估算模式。对改进模式与传统模式的臭氧总量初估结果表明,传统模式依赖于指数模型的拟合精度,而改进模式依赖于对数模型的拟合精度,指数模型和对数模型均表现出高的拟合精度,但对数模型的拟合精度比指数模型在整个臭氧浓度范围内平均高约0.9%。改进模式使臭氧总量初估的总体精度得到改善,RMSE降低约0.087%~0.537%,并且在较大观测几何和臭氧总量低值区（175~275DU）间则更加显著。在臭氧总量低值区间以及较大观测天顶角和太阳天顶角条件下,改进模式具有更高的估算精度和更大的适用范围。该改进的臭氧总量初值估算模式可为日后TOMS算法的更新提供支持和参考依据。New hyperspectral sensor to detect total ozone is considered to be carried on geostationary orbit platform in the future,because local troposphere ozone pollution and diurnal variation of ozone receive more and more attention.Sensors carried on geostationary satellites frequently obtain images on the condition of larger observation angles so that it has higher requirements of total ozone retrieval on these observation geometries.TOMS V8 algorithm is developing and widely used in low orbit ozone detecting sensors,but it still lack of accuracy on big observation geometry,therefore,how to improve the accuracy of total ozone retrieval is still an urgent problem that demands immediate solution.Using moderate resolution atmospheric transmission,MODTRAN,synthetic UV backscatter radiance in the spectra region from 305 to 360nm is simulated,which refers to clear sky,multi angles（12solar zenith angles and view zenith angles）and 26 standard profiles,moreover,the correlation and trends between atmospheric total ozone and backward scattering of the earth UV radiation are analyzed based on the result data.According to these result data,a new modified initial total ozone estimation model in TOMS V8 algorithm is considered to be constructed in order to improve the initial total ozone estimating accuracy on big observation geometries.The analysis results about total ozone and simulated UV backscatter radiance shows：Radiance in 317.5nm（R317.5）decreased as the total ozone rise.Under the small solar zenith Angle（SZA）and the same total ozone,R317.5decreased with the increase of view zenith Angle（VZA）but increased on the large SZA.Comparison of two fit models shows：without the condition that both SZA and VZA are large（〉80°）,exponential fitting model and logarithm fitting model all show high fitting precision（R20.90）,and precision of the two decreased as the SZA and VZA rise.In most cases,the precision of logarithm fitting mode is about 0.9% higher than exponential fitting model.With the increasing of VZA

关 键 词：臭氧总量 TOMS V8算法 地球紫外后向散射 太阳天顶角 观测天顶角 DU 

分 类 号：TP7[自动化与计算机技术—检测技术与自动化装置]