【作者】 张丽莉；

【导师】 赵云升；

【作者基本信息】 东北师范大学 ， 地图学与地理信息系统， 2013， 硕士

【摘要】 在全球变暖加剧的形势下，融雪对淡水资源管理、融雪灾害和全球气候变化等方面的影响越来越大，传统遥感对于固态雪的研究已无法满足需求。本文以偏振光遥感理论为基础，实验室测量不同类型的融雪在400—2400nm波段范围内的偏振光谱，通过分析光线入射天顶角、探测天顶角、方位角和偏振角对不同类型融雪的影响，得出具有诊断意义的光谱特征。基于融雪类型、方位角和光谱波段进行三因素三水平的正交试验。得出如下的结论：（1）融雪光谱变化趋势。400-760nm波段，融雪的偏振反射比很高，偏振反射光谱曲线变化平缓。760-1500nm波段融雪偏振光谱波动较大，1500-2400nm波段，干雪、潮雪和湿雪的偏振反射光谱具有明显的两峰三谷，水湿雪的偏振反射光谱曲线趋近于一个常数。（2）诊断性光谱特征。400-760nm波段，融雪在90°偏振时的反射比最大，45°偏振次之，0°偏振最小；融雪偏振反射光谱随探测角和入射角变化而出现的重合或分离状态是判断积雪融化程度的一个方法。760-1500nm波段，融雪偏振光谱曲线的拟合点和拟合效果是区分干雪和融化状态雪的显著标志；融雪偏振反射光谱随方位角度的变化趋势和在近红外波段的拟合趋势可以用来区分融雪含水量的大小；随入射天顶角的变化，融雪偏振反射光谱曲线截止点处的波长是判断融雪含水量大小的一个标志。1500-2400nm波段，不同入射角变化的条件下，融雪偏振反射光谱缺失的波段范围大小，也可以用来判断积雪融化程度。随入射角和探测角的增加各类型融雪的偏振反射比增加，随雪中含水量的增加，各类型融雪的偏振反射比降低。潮雪和湿雪在180°方位角时出现反常的光谱特征。（3）监测融雪偏振反射光谱的最佳条件为潮雪700nm波段135°方位角。了解不同类型融雪光谱的偏振影响因素，为进一步分析融雪的偏振特性奠定了基础，为融雪的动态监测提供了条件，同时对淡水资源管理、全球气候变化和相关融雪灾害研究也有重要的现实意义。更多还原

【Abstract】 Under the situation of global warming intensifies, snow melting has more and moreinfluence on the management of freshwater resources、melting snow disasters、global climatechange and so on, traditional remote sensing has been unable to meet demand for the study ofsolid snow. In this paper, based on the theory of polarization remote sensing, laboratorymeasures polarization spectra of different types of snowmelt in the400-2400nm band range,by analyzing the light incident zenith Angle, detection zenith Angle, azimuth Angle andpolarization Angle of the influence of different kinds of snowmelt, the diagnostic significanceof spectral characteristics are obtained. Three factors and three levels orthogonal test wascarried out based on snowmelt type, azimuth Angle and spectral band. Leads to the followingconclusions:(1) Snowmelt spectral change trend. The polarization of the melting snow reflectance isvery high in400-760nm band, the polarization spectral reflectance curve flat. Snowmeltpolarization spectrum fluctuation is bigger in760-1500nm band, the polarization spectralreflectance of dry snow, tide snow and wet snow has obvious two peaks and three valleys in1500-2400nm bands, the polarization spectral reflectance curves of water wet snow tends tobe a constant.(2) Diagnostic spectral features. In400-760nm band, the reflectance of snow melt is thebiggest at90degree polarization, followed by45degree polarization,0degree polarization isthe smallest; Changing with detection Angle and incident Angle, snowmelt polarizationreflection spectrum appears state of coincidence or separation, which is a method of judgingthe snow melting degree. In760-1500nm band, the fitting point and fitting effect of snowmeltpolarization spectrum curve is significant signs to distinguish the dry snow and state ofmelting snow; Snowmelt polarization reflection spectrum with the tendency of the azimuthAngle and fitting of trends in the near infrared wave band can be used to distinguish betweenthe size of the melting snow water content; Along with the change of the incident zenithAngle, the wavelength of snowmelt polarization spectral reflectance curve cut-off points is asign of melting snow water content size. In1500-2400nm bands, on the condition of differentincidence Angle changing, lack of snowmelt polarization spectral reflectance of band size, canalso be used to determine degree of melting snow. With the increase of the incidence Angleand detection Angle, each type of polarization of the melting snow reflectance increases, withthe increase of water content in snow, each type of polarization of the melting snowreflectance reduces. Tide snow and wet snow appear abnormally spectral characteristics at180degree Angle.(3) The best condition of monitoring snowmelt polarization spectral reflectance is tidesnow700nm band135degree Angle.Understanding different types of snowmelt spectrum polarization of the influencingfactors, which laid a foundation for further analyzing the polarization characteristics ofsnowmelt, provides conditions for the dynamic monitoring of melting snow, at the same time,it also has important practical significance in the management of freshwater resources, globalclimate change and melting snow disaster research.更多还原