使用FieldSpec 3(350~2 500 nm)光谱仪野外测得新疆富蕴地区季节性积雪光谱,与冰对比得出了该地区典型季节性积雪光谱特征,并分析了太阳高度角、 坡度、 雪深、 污染物浓度对积雪光谱的影响。研究结果表明:积雪反射率在可见光波段较高,随波长的增加逐渐减小;随着太阳高度角的增大积雪反射率逐渐降低,且在1 090和1 300 nm对太阳高度角的变化敏感;坡度的存在使积雪反射率大幅上升;在一定深度范围内,积雪反射率随雪深的增加而增大,在400~500和1 250~1 320 nm,反射率对雪深变化敏感;随着污染物的增加,积雪反射率在可见光波段明显下降,且波峰波谷趋于平缓。季节性积雪的光谱测量和分析工作对于积雪参数的监测和反演具有重要意义。
Seasonal snow reflectance in the spectral range 350-2 500 nm was collected by a portable spectroradiometer in the field. The experiments were carried out in Fuyun County, Xinjiang Province. Spectral characteristics of snow in the region were drawn by the contrast with ice. And the influence of solar elevation angle, slope, snow depth and contamination on snow reflec- tance was analyzed. The observations suggest that snow reflectance is high in visible light range and decreases gradually with increasing wavelength. As the solar elevation angle increases, snow reflectance decreases and the maximum variations are observed around 1 090 and 1 300 nm. For the existence of slope, snow reflectance rises significantly. As snow depth increases locally, snow reflectance increases and the maximum variations are observed around 400-500 and 1 250- 1 320 nm. As contamination content increases, snow reflectance decreases and troughs and crests of spectral curve flatten. The measurement and analysis of seasonal snow reflectance are of great significance for monitoring and retrieval of snow characteristics.