山区气溶胶多角度偏振遥感地气解耦方法评估  

Evalutaion of land-atmospheric decoupling methods for mountainous aerosol multi-angle polarization remote sensing

作　　者：翟颖超 王涵 赵梅如 陈科 李林森 ZHAI Yingchao;WANG Han;ZHAO Meiru;CHEN Ke;LI Linsen(College of Surveying and Land Information Engineering,Henan Polytechnic University,Jiaozuo 454000,China;School of Environment and Spatial Informatics,China University of Mining and Technology,Xuzhou 221116,China;School of Geography and Tourism,Anhui Normal University,Wuhu 241000,China)

机构地区：[1]河南理工大学测绘与国土信息工程学院,河南焦作454000 [2]中国矿业大学环境与测绘学院,江苏徐州221116 [3]安徽师范大学地理与旅游学院,安徽芜湖241000

出　　处：《大气与环境光学学报》2023年第4期339-356,共18页Journal of Atmospheric and Environmental Optics

基　　金：国家自然科学基金(42075132)。

摘　　要：山区复杂的地形特征会导致地表反射率估算误差增加,降低地气解耦精度,进而影响气溶胶反演精度。当前应用较广泛的反演方法有基于波段关系估算地表反射的暗目标算法(DT)、基于区域地表反射率库的深蓝算法(DB)和基于双向反射分布函数(BRDF)、双向偏振分布函数(BPDF)模型估算地表反射率的GRASP(Generalized retrieval of atmosphere and surface properties)算法。为探究适合山区气溶胶遥感的地气解耦方法,利用地面气溶胶自动观测网(AERONET)气溶胶产品(AOD_A)对比分析了2005年至2013年间POLDER-3(Polarization and directionality of the earth's reflectances)的GRASP气溶胶产品(AOD_G)、中等分辨率成像光谱仪(MODIS)的DT气溶胶产品(AOD_DT)和DB气溶胶产品(AOD_DB)在中国区域的精度。结果显示,非山区站点处AOD_G与AOD_A整体相关性最高(R=0.921),AOD_DT和AOD_DB总体精度差异不大,但山区AOD_G高于期望误差的比例达79.87%,AOD_DT和AOD_DB高估程度分别增加了近30%和20%。在河北兴隆和兰州大学半干旱气候与环境观测站(SACOL)两个山区站点分季节验证显示,植被覆盖度低的秋冬季节三种卫星产品精度均存在下降趋势,表明除去地表植被对反射率的影响后,山区地形影响了地气解耦精度。进一步分析显示,山区起伏地形对基于BRDF、BPDF模型的地气解耦方法影响较大;在山区等起伏地表上空,多角度观测的地表波段关系更有利于精确估算地表反射,而在城区BRDF、BPDF模型与波段关系估算地表反射的误差水平接近。研究结果为进一步优化多角度观测(如高分五号DPC)的山区气溶胶反演算法提供了新的方向。The complex terrain characteristics of mountainous areas can increase the estimation error of surface reflectance,reduce the accuracy of land-atmospheric decoupling,and then affect the accuracy of aerosol retrieval.Currently,the widely used retrieval methods include the dark target algorithm(DT)based on the band relationship to estimate the surface reflectance,the deep blue algorithm(DB)based on the regional surface reflectance library,and the generalized retrieval of atmosphere and surface properties(GRASP)algorithm based on the bidirectional reflectance distribution function(BRDF)and bidirectional polarization distribution function(BPDF)model to estimate the surface reflectance.To explore the land atmospheric decoupling methods suitable for aerosol remote sensing in mountainous areas of China,the accuracy and applicability of GRASP aerosol optical depth(AOD_G)of polarization and directionality of the earth's reflectances(POLDER-3),DT aerosol optical depth(AOD_DT)and DB aerosol optical depth(AOD_DB)of moderate resolution imaging spectroradiometer(MODIS)in China from 2005 to 2013 were compared and analyzed using AErosol RObotic NETwork(AERONET)aerosol optical depth(AOD_A).The results show that the overall correlation between AOD_G and AOD_A at non-mountainous sites is the highest(with correlation coefficient R=0.921),and the overall accuracy of AOD_DT and AOD_DB is not much different.However,the proportion of AOD_G higher than the expected error in mountainous areas is 79.87%,and the overestimation proportion of AOD_DT and AOD_DB increases by nearly 30% and 20%,respectively.Seasonal validation at two mountain sites,Xinglong in Hebei Province and Seimi-Arid Climate and Environment Observatory of Lanzhou University(SACOL),shows that the accuracy of all three satellite products tend to decrease in the autumn and winter seasons when the vegetation cover is low,indicating that the mountain topography can affect the accuracy of land-atmosphere decoupling after removing the influence of surface vegetation on reflectance

关 键 词：山区 多角度偏振 气溶胶光学厚度 地气解耦 

分 类 号：P422[天文地球—大气科学及气象学]