Measuring Snow Liquid Water Content with Low-Cost GPS Receivers
Measuring Snow Liquid Water Content with Low-Cost GPS Receivers
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DOI：
10.3390/s141120975
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发表时间：
2014-11-01
期刊：
影响因子：
3.9
通讯作者：
Mauser, Wolfram
中科院分区：
文献类型：
--
作者：
Koch, Franziska;Prasch, Monika;Mauser, Wolfram
雪中液态水的含量是积雪湿度的特征。它的时间演变起着重要的作用，湿雪雪崩预测，以及在一个流域内的融水释放和水的可用性估计的发病。然而，利用常规的原位和遥感技术测量雪中液态水含量仍然是一个具有挑战性且尚未得到很好解决的问题。我们提出了一种新的方法的基础上，在L波段的全球定位系统（GPS）的卫星发射的微波辐射的衰减。为此，我们于2013年融雪期在瑞士的Weissfluhjoch试验场进行了连续的低成本GPS测量实验。作为信号强度的度量，我们分析了载噪功率密度比（C/N-0），并开发了一个程序来归一化这些数据。散装体积LWC的基础上确定的衰减，反射和折射的辐射在湿雪的假设。融化的开始，以及每天的融化-冷冻循环被清楚地检测到。LWC的时间演变与气象和雪水资料密切相关。由于其非破坏性的设置，其成本效益和全球可用性，这种方法有可能被实施在分布式传感器网络的雪崩预测或流域范围内的融化开始测量。
The amount of liquid water in snow characterizes the wetness of a snowpack. Its temporal evolution plays an important role for wet-snow avalanche prediction, as well as the onset of meltwater release and water availability estimations within a river basin. However, it is still a challenge and a not yet satisfyingly solved issue to measure the liquid water content (LWC) in snow with conventional in situ and remote sensing techniques. We propose a new approach based on the attenuation of microwave radiation in the L-band emitted by the satellites of the Global Positioning System (GPS). For this purpose, we performed a continuous low-cost GPS measurement experiment at the Weissfluhjoch test site in Switzerland, during the snow melt period in 2013. As a measure of signal strength, we analyzed the carrier-to-noise power density ratio (C/N-0) and developed a procedure to normalize these data. The bulk volumetric LWC was determined based on assumptions for attenuation, reflection and refraction of radiation in wet snow. The onset of melt, as well as daily melt-freeze cycles were clearly detected. The temporal evolution of the LWC was closely related to the meteorological and snow-hydrological data. Due to its non-destructive setup, its cost-efficiency and global availability, this approach has the potential to be implemented in distributed sensor networks for avalanche prediction or basin-wide melt onset measurements.