二向反射模型在土地覆被制图中的应用

Application of BRDF model in land cover mapping

植被的反射异质性特征可以反映植被的结构和光谱特性,有助于更有效地识别植被.在塔里木河下游开展的研究中,使用了MISR的多角度观测数据,利用核驱动和RPV模型反演获取地表BRDF信息,使用SVM方法对MISR天底角反射率数据和BRDF信息组合进行土地覆被分类研究,对比分析了BRDF对分类效果的影响.发现:①BRDF信息可以为半干旱区土地覆被制图提供附加的有用信息,提高制图的精度.②核驱动模型和RPV模型都能较好地模拟研究区地表反射的状况.③空间结构差异较大的草地和林地类型使用BRDF信息后的用户精度明显提高.

The reflection heterogeneity of vegetation can reflect the structural and spectral characteristics of vegetation,and therefore it can help to identify vegetation more effectively.Misr multi-angle observation data has been explored in the sutdy of the lower Tarim River.Meanwhile,the kernel driven and RPV model inversion is used to obtain information of surface BRDF,and SVM method is used to study the land use and the cover of classification by the combination of MISR nadir reflectance data and BRDF information.By comparative analysis of the effect of the BRDF of the classification results,the findings are as following：①BRDF information can provide additional information for the land cover mapping in the semi-arid area and improve the accuracy of the mapping.②Both the kernel driven model and the RPV model can simulate the surface reflection in the study area.③After using BRDF,the identification accuracy of grassland and forest land increased obviously.