Determining snow water equivalent (SWE) in a fast and nondestructive way is a key request for many hydrologists and snow scientists. To this aim, microwave ground-based radars represent a viable solution, but often the simultaneous measurement of both the snowpack depth and density (the key ingredients for the SWE) is very complex, inaccurate, or requires difficult procedures and equipment. This letter presents a novel radar technique for self-standing calculation of the SWE that can be applied to bi-static radars. This technique, based on the multipath propagation of the radar signal into the snowpack, only requires a radar with two fixed antennas, without any other device, movement of the antennas, or a priori empirical assumptions. This makes such a technique particularly suitable for light and portable radars for rapidly probing large areas, providing, for example, an innovative validation means for satellite-based microwave remote sensing methods. The proposed technique was demonstrated using a stepped frequency modulated continuous wave (FMCW) radar in field conditions for dry snow, delivering results for snow depth and SWE, benchmarked by manual analyses of the snowpack, with a mean absolute error better than 5 cm.

中文翻译：

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使用地基雷达的多径传播确定干雪堆的雪水当量

以快速且无损的方式确定雪水当量 (SWE) 是许多水文学家和雪科学家的关键要求。为此，微波地基雷达是一种可行的解决方案，但通常同时测量积雪深度和密度（SWE 的关键要素）非常复杂、不准确，或者需要困难的程序和设备。这封信提出了一种用于独立计算 SWE 的新型雷达技术，该技术可应用于双基地雷达。这种技术基于雷达信号进入积雪的多径传播，只需要一个带有两个固定天线的雷达，不需要任何其他设备、天线的移动或先验的经验假设。这使得这种技术特别适合用于快速探测大面积的轻型和便携式雷达，例如，为基于卫星的微波遥感方法提供一种创新的验证手段。所提出的技术在干雪的现场条件下使用步进调频连续波 (FMCW) 雷达进行了演示，提供了雪深和 SWE 的结果，以积雪的手动分析为基准，平均绝对误差优于 5 厘米。