光子学报, 2018, 47 (6): 0612004, 网络出版: 2018-09-07
敦煌辐射校正场春季BRDF特性分析
Analysis of the BRDF Characteristics of Dunhuang Radiometric Calibration Site in the Spring
遥感 场地定标 双向反射分布函数 双向反射分布函数模型 春季敦煌 方向反射比 Remote sensing Field calibration BRDF BRDF model Dunhuang in spring Directional reflectance MODIS MODIS
摘要
风云四号A星在轨替代定标试验于2017年4月下旬在敦煌辐射校正场正式开展, 为满足地表反射率在遥感器视角方向上的校正需求, 利用便携式定点测量装置对敦煌戈壁地表进行了方向特性测量.定性分析了敦煌场地春季的方向特性, 并基于RossThick-LiSparseR核驱动模型反演了相应的双向反射分布函数模型参数, 构建了场地方向特性定量描述模型.对模型的计算值与实测数据进行线性回归分析, 得到2017年4月26日、27日和28日的修正决定系数分别在0.75、0.83和0.85左右, 验证了该模型对实测数据具有良好的拟合优度.利用模型计算太阳方位面上的各向异性因子并与中分辨率成像光谱仪双向反射分布函数模型参数产品的历史数据进行对比发现, 当观测天顶角小于40°时, 二者相对偏差在波段2和波段4均小于1.56%, 波段5小于3.12%.这说明构建的模型能较好地描述敦煌场地方向特性, 验证了试验数据的可靠性.
Abstract
An on-orbit vicarious calibration experiment for FY-4A was formally performed at Dunhuang Radiometric Calibration Site in late April, 2017. In order to meet the needs of the directional corrections in the sensor viewing angle of surface reflectances, the Dunhuang Gobi surface directional reflectances were measured using a portable measurement instrument. The spring directional reflection characteristics of Dunhuang site were qualitatively analyzed and the parameters of bidirectional reflectance distribution function model were inversed based on the RossThick-LiSparseR kernel-driven model. The linear regression analysis was performed for the calculated data and the measured data, the adjusted R-Square of April 26th, 27th and 28th, 2017 are 0.75, 0.83 and 0.85, and the present model had proven to provide a good fit to measured data. The anisotropy factors in the solar principal plane were obtained by utilizing model and compared with historical data of moderate-resolution imaging spectroradiometer BRDF/Albedo model parameters product. The relative deviation of band 2 and band 4 were below 1.56% and the band 5 was below 3.12% when the view zenith angle was less than 40 degrees. The results demonstrate that the constructed model can pretty describe the directional reflection characteristics of Dunhuang site, and verify the reliability of measured data.
余谭其, 韦玮, 张艳娜, 张运杰, 李新, 郑小兵, 孙凌. 敦煌辐射校正场春季BRDF特性分析[J]. 光子学报, 2018, 47(6): 0612004. YU Tan-qi, WEI Wei, ZHANG Yan-na, ZHANG Yun-jie, LI Xin, ZHEN Xiao-bing, SUN Ling. Analysis of the BRDF Characteristics of Dunhuang Radiometric Calibration Site in the Spring[J]. ACTA PHOTONICA SINICA, 2018, 47(6): 0612004.