作　　者： ; ; ;

机构地区： 中国科学院寒区旱区环境与工程研究所

出　　处： 《冰川冻土》 2014年第2期386-393,共8页

摘　　要： 双向反射分布函数(BRDF,Bidirectional Reflectance Distribution Function)反演作为定量遥感的重要研究方向,其定量化地描述了地表反射的各向异性特点.传统的积雪BRDF反演主要采用ROSS+LI核,采用贝叶斯概率统计的方法或者采用最小二乘的方法进行求解系数,方法简单可行,但是这些模型对积雪的物理特性定量描述不是太全面.积雪是一个复杂的体系,众多因素对BRDF影响较大,如雪粒径与雪污化物,传统的ROSS+LI核不能定量地描述这些因素对积雪的BRDF的影响.渐进辐射传输算法,以其计算简单,运算速度快而不降低辐射传输的精度,被广泛地运用到定量遥感之中.利用此理论进行积雪BRDF反演及验证,首先进行积雪的雪粒径反演,采用了渐进辐射传输模型建立光谱库;其后确定中心波长1.03μm作为最佳雪粒径反演波段,同时采用此理论反演了雪污染量;最后利用已有的雪粒径与反演的相对污化物含量进行BRDF重构.实验表明:基于渐进辐射传输的积雪BRDF具有可行性,精度能够满足生产之用,同时产生的中间产品,如雪粒径、雪污染等,可以广泛地运用于生产实践之中.通过此方法能够有效地将积雪遥感的雪粒径、雪污染、BRDF串联起来,方便积雪快速定量化描述. Bidirectional Reflectance Distribution Function （BRDF） is an important research direction of quantitative remote sensing, which is able to quantitatively describe the anisotropic characteristics of surface reflection. Traditional snow BRDF retrieval is mainly based on the ROSS ＋ LI kernel function, the Bayesian probability theory or mathematical statistics methods to acquire least squares coefficients. These methods were simple and feasi- ble, but quantitative descriptions of the physical characteristics of snow were not comprehensive enough. Snow was a complex system, and a number of factors impact its BRDF, such as particle size and pollutant, while tradi- tional ROSS ＋ LI kernel couldn＇t quantitatively describe the impact of these factors on snow BRDF. The asymp- totic radiative transfer （ART） model, in terms of their simple, fast and not reducing the accuracy of radiative transfer calculations, is widely used in the quantitative remote sensing. In this paper, ART model is used to re- verse and validate snow BRDF. Firstly the sensitive band of retrieved snow grain size was analyzed, and then the band of 1.03μm was finalized to be the best band of snow particle size for inversion. Meanwhile, relative pollution amounts of snow were retrieved, and finally snow particle size and pollution content were used as input parameters for BRDF reconstruction. Experiments showed that retrieval of snow BRDF based on ART is feasible. At the same time, the intermediate product, such as snow particle size and snow pollution content, could be broadly used in production practice. ART model is able to effectively connecting snow particle size, snow pollution content and BRDF, easy to quantitatively describe snow physical characteristics.

关 键 词： 渐进辐射传输 雪粒径 雪污化物含量

领　　域： [自动化与计算机技术] [自动化与计算机技术]