大气与环境光学学报 ›› 2023, Vol. 18 ›› Issue (4): 339-356.

• 高分五号 02 星偏振载荷在轨测试和信息处理 • 上一篇    下一篇

山区气溶胶多角度偏振遥感地气解耦方法评估

翟颖超 1, 王涵 2*, 赵梅如 3, 陈科 1, 李林森 1   

  1. 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
  • 收稿日期:2022-10-13 修回日期:2022-12-16 出版日期:2023-07-28 发布日期:2023-08-14
  • 通讯作者: E-mail: ms.h.wang@cumt.edu.cn E-mail:ms.h.wang@163.com
  • 作者简介:翟颖超 (1998- ), 女, 河南鹿邑人, 硕士研究生, 主要从事大气遥感方面的研究。E-mail: 212004010025@home.hpu.edu.cn
  • 基金资助:
    国家自然科学基金 (42075132)

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

ZHAI Yingchao 1, WANG Han 2*, ZHAO Meiru 3, CHEN Ke 1, LI Linsen 1   

  1. 1 College of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo 454000, China; 2 School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China; 3 School of Geography and Tourism, Anhui Normal University, Wuhu 241000, China
  • Received:2022-10-13 Revised:2022-12-16 Published:2023-07-28 Online:2023-08-14

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。

关键词: 山区, 多角度偏振, 气溶胶光学厚度, 地气解耦

Abstract: 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 landatmospheric 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. Further analysis shows that the mountainous terrain has a great influence on the land-atmosphere decoupling method based on BRDF and BPDF model. The multi-angle observation of surface band relationship is more conducive to accurate estimation of surface reflection over undulating surface such as mountainous areas, while there is no significant difference of estimating surface reflection between BRDF/BPDF models and band relationships in urban areas. The results provide a new direction for further optimizing the multi-angle observation (such as Gaofen-5 DPC) aerosol retrieval algorithm in mountainous areas.

Key words: mountainous areas, multi-angle polarization, aerosol optical depth, land-atmospheric decoupling

中图分类号: