【摘要】 根据适合于垂直单角度观测的GeoSAIL模型,改进得到适合于各种角度观测的MGeoSAIL模型。它是几何光学模型和辐射传输模型的结合。具备两种模型的优点使MGeoSAIL模型更具准确性和实用性。其中几何光学模型用来计算场景内不同情况下阴影和光照成分的比例,辐射传输模型(SAIL)考虑冠层内的辐射传输计算得到树冠的反射率和投射率,将其权重加和生成场景反射率。模拟结果表明该模型简单实用,在可见光与近红外波段均能反映出"热点"效应,在近红外波段能描述出"碗边"效应,且更适合于低密度、大个体、不连续稀疏林分冠层的BRDF模拟。更多还原

【Abstract】 A MGeoSAIL model,which is more suitable for multi-angle observations,is constructed based on the improvement of the single-angle model GeoSAIL.The MGeoSAIL model combines the geometric-optical model with the radiation transfer model.Therefore,it has the advantages of the two models,which made it more accurate and practicable.The geometric-optical model calculates the amount of shadowed and illuminated components in a scene,while the radiation transfer model(SAIL) calculates the reflectance and transmittance of the tree crowns.The reflectance of each component in a scene is weighted by its fractional area and summed.The simulation result showes that the MGeoSAIL model could be simple and applicable to describe the "hot" spot in visible and near-infrared bands,and the "bowl" shape in the near-infrared band.Furthermore,the model is demonstrated to be more suitable in the BRDF simulation of discontinuous and open forest with low density and large individuals.更多还原