大气与环境光学学报, 2016, 11 (2): 125, 网络出版: 2016-03-29
基于航空偏振数据的地表BPDF模型优化研究
Model Optimization of Didirectional Polarization Reflectance Distribution Function of Land Surface Based on Airborne Polarimetric Data
摘要
针对航空偏振气溶胶反演涉及的地表双向偏振辐射分布函数(BPDF)特性问题,分析了地表双向偏振反射分布物理机理,结合经典地表BPDF模型 参数特点,提出了基于阴影方程和归一化植被指数的优化地表BPDF模型。利用航空辐射偏振遥感数据,验证了新模型的精度,相对于实测结果,平均 相对偏差小于9.9%。与三种经典模型模拟结果相比,新模型值随不同观测角度变化时,其一致性很好。根据新模型精度,还模拟了地表偏振反 射率偏差与气溶胶光学厚度反演误差的关系,发现地表偏振反射率偏差为4×10-4时,带来反演气溶胶光学厚度误差小于0.03,满 足气溶胶偏振反演应用要求。
Abstract
For the characteristic problem of bidirectional polarization reflectance distribution function (BPDF) in airborne polarimetric aerosol optic depth retrieval, the physics mechanism of BPDF is analyzed, and a BPDF model is put forward combining the characteristic BPDF model with the four classical models. This model is based on the shadow function and normalized difference vegetation index factor. The accuracy of new model is validated by the data of atmosphere multi-angle polarization radiometer, and the relative error is less than 9.9%. Compared with the three classic models, the new model shows good consistency when the viewing angle changes. Based on the accuracy of the new model, the relationship is simulated between the bias of polarized reflectance of land surface and the error of the retrieved aerosol optic depth. The results indicate that only less than 0.03 of the absolute error of the retrieved aerosol optic depth is caused when the polarized reflectance of land surface changed 4×10-4, and the application requirement of polarized aerosol retrieve can be satisfied.
舒存铭, 孙晓兵, 王涵, 龚冠源. 基于航空偏振数据的地表BPDF模型优化研究[J]. 大气与环境光学学报, 2016, 11(2): 125. SHU Cunming, SUN Xiaobing, WANG Han, GONG Guanyuan. Model Optimization of Didirectional Polarization Reflectance Distribution Function of Land Surface Based on Airborne Polarimetric Data[J]. Journal of Atmospheric and Environmental Optics, 2016, 11(2): 125.