雪粒径大小影响着积雪反照率的高低,从而影响着局地或全球能量收支平衡和气候变化,其影响程度取决于积雪本身的微物理特征和光学特性.在研究550—1030和1640hm波长处积雪光学特性的基础上,采用辐射传输方程模拟并分析了雪粒径对积雪双向反射率的影响.模拟结果表明近红外通道1030nm是反演雪粒径的敏感波长,积雪双向反射率在该波段随粒径和观测角度变化明显,多角度遥感信息可以更有效地体现积雪的微物理特征和光学特性,为利用多角度遥感数据反演雪粒径提供理论基础.
The snow albedo which is influenced by the snow grain size, plays an important role in regional or global ra- diation balance and climate change. The degree of influence depends on the microphysical and optical properties of snow. In this paper, the influence of snow grain size on sensitivity of snow bidirectional reflectance was simulated and analyzed by the radiative transfer equation based on the studies of snow optical characteristics in 550 nm, 1030nm and 1 640 nm. The results indicate that the near-infrared channel 1 030 nm is the sensitive wavelength to retrieve snow grain size. In this band, snow bidirectional reflectance changes significantly when grain size and view angle change. This stud- y provides the theoretical basis for retrieving snow grain size with the multi-angular remote sensing data.