The Quantitative Analysis Of The Polarization Characteristics Of The Melting Snow

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.