Two-dimensional radar imaging of flowing avalanches

Radar has emerged as an important tool in avalanche research. However, existing radar sensors suffer from coarse range resolution capabilities. This limits the usefulness of the data they collect in validating models of avalanche dynamics. This paper details the development of a frequency modulated continuous wave, phased array radar, and its associated signal processing, for non-invasive measurements of entire avalanche events. The radar outperforms existing avalanche radar sensors in terms of range resolution, and it provides cross-range resolution using a phased array receiver. The radar has been operating at the Vallee de la Sionne avalanche test site in Switzerland since the 2010 winter season. It has successfully gathered measurements of entire natural avalanche events. In this paper we show two-dimensional radar images of a naturally occurring avalanche, the first of their kind, which reveal movements of layers or particles of the flowing avalanche in unparalleled detail. Furthermore, the potential of the measured data is shown with tracking of avalanche fronts in two spatial dimensions. This marks an important step towards providing a library of high-quality avalanche measurements to improve our knowledge of avalanche dynamics. (C) 2014 Elsevier B.V. All rights reserved.

雷达已成为雪崩研究中的一种重要工具。然而，现有的雷达传感器存在距离分辨率粗糙的问题。这限制了它们所收集的数据在验证雪崩动力学模型方面的有效性。本文详细介绍了一种调频连续波相控阵雷达及其相关信号处理的研发情况，用于对整个雪崩事件进行非侵入式测量。该雷达在距离分辨率方面优于现有的雪崩雷达传感器，并且它利用相控阵接收器提供横向距离分辨率。自2010年冬季以来，该雷达一直在瑞士锡永山谷雪崩试验场运行。它已成功收集了整个自然雪崩事件的测量数据。在本文中，我们展示了一次自然发生的雪崩的二维雷达图像，这是此类图像中的首张，它以无与伦比的细节揭示了流动雪崩的层或颗粒的运动。此外，通过在两个空间维度上对雪崩前沿进行追踪，展示了测量数据的潜力。这标志着朝着提供一个高质量雪崩测量数据库以增进我们对雪崩动力学的了解迈出了重要的一步。（C）2014爱思唯尔有限公司。保留所有权利。