In situ effective snow grain size mapping using a compact hyperspectral imager
In situ effective snow grain size mapping using a compact hyperspectral imager
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DOI：
10.1017/jog.2020.68
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发表时间：
2021-02-01
影响因子：
3.4
通讯作者：
Hammonds, Kevin
中科院分区：
文献类型：
--
作者：
Donahue, Christopher;Skiles, S. McKenzie;Hammonds, Kevin
有效雪粒半径（r（e））映射在高分辨率使用近红外高光谱成像（NIR-HSI）。NIR-HSI方法可用于量化r（e）的空间变异性，由于变质作用而引起的r（e）变化，并可视化积雪中的水渗透。结果是三个不同的实验室制备的雪样品（均匀，冰透镜，细颗粒的粗颗粒），其侧壁之前和之后的太阳能灯诱导融化成像。使用以1030 nm为中心的冰吸收特征的缩放带区域，将每个类似于3 mm像素的光谱反射率反转为r（e），产生由54 740个像素组成的r（e）图。所有的雪样品表现出颗粒粗化后融化的结果，湿雪变质，这是量化的r（e）分布的变化，从前和融化后的图像。将NIR-HSI方法与来自现场光谱仪和X射线计算机微断层扫描（micro-CT）的r（e）检索进行比较，结果光谱仪具有相同的平均r（e），而micro-CT的平均r（e）比高光谱成像仪高23.9%。随着紧凑的高光谱成像仪变得越来越广泛，这种方法可能是一个有价值的工具，用于评估r（e）的空间变异性和雪变质在现场和实验室设置。
Effective snow grain radius (r(e)) is mapped at high resolution using near-infrared hyperspectral imaging (NIR-HSI). The NIR-HSI method can be used to quantify r(e) spatial variability, change in r(e) due to metamorphism, and visualize water percolation in the snowpack. Results are presented for three different laboratory-prepared snow samples (homogeneous, ice lens, fine grains over coarse grains), the sidewalls of which were imaged before and after melt induced by a solar lamp. The spectral reflectance in each similar to 3 mm pixel was inverted for r(e) using the scaled band area of the ice absorption feature centered at 1030 nm, producing r(e) maps consisting of 54 740 pixels. All snow samples exhibited grain coarsening post-melt as the result of wet snow metamorphism, which is quantified by the change in r(e) distributions from pre- and post-melt images. The NIR-HSI method was compared to r(e) retrievals from a field spectrometer and X-ray computed microtomography (micro-CT), resulting in the spectrometer having the same mean r(e) and micro-CT having 23.9% higher mean r(e) than the hyperspectral imager. As compact hyperspectral imagers become more widely available, this method may be a valuable tool for assessing r(e) spatial variability and snow metamorphism in field and laboratory settings.