On pulsed Doppler radar measurements of avalanches and their implication to avalanche dynamics
On pulsed Doppler radar measurements of avalanches and their implication to avalanche dynamics
复制标题
DOI：
10.1016/j.coldregions.2007.03.009
复制
发表时间：
2007-11-01
影响因子：
4.1
通讯作者：
Schreiber, Helmut
中科院分区：
文献类型：
--
作者：
Gauer, Peter;Kern, Martin;Schreiber, Helmut
脉冲多普勒雷达测量从几个雪崩释放进行了分析，以深入了解雪崩动力学。脉冲多普勒雷达发射短脉冲，并在不同的时间间隔内对回波进行采样，对应于距离间隔（距离门）。利用多普勒效应对回波信号进行频率分析，得到距离门宽度内的速度分布。因此，可以获得关于沿着轨道的前沿速度的信息以及关于沿着轨道的特定位置处的速度与时间的关系的信息。除了雪崩速度之外，还可以导出关于沿着轨道的加速度/减速度的大小的信息。为此，一对相邻的距离门的速度进行比较。加速度/减速度值可以为常用数值雪崩模型的摩擦项参数提供提示。推导出的减速加速度意味着不同的行为在这些模型中提出的。它们还表明了减速加速度对流动阶段的依赖性。(C)2007 Elsevier B. V.保留所有权利。
Pulsed Doppler radar measurements from several avalanche releases are analyzed to gain an in-depth understanding of avalanche dynamics. A pulsed Doppler radar emits short pulses and samples the echo in distinct time intervals, corresponding to distance intervals (range gates). Frequency analysis of the echo signals, exploiting the Doppler-effect, yields the velocity distribution within the width of a range gate. Thus, it is possible to gain information on the front speed along the track and information on the velocity versus time at a specific location along the track.In addition to the avalanche velocity, information on the magnitude of accelerations/decelerations along the track can be derived. To this end, the velocities of a pair of adjoining range gates are compared. The acceleration/deceleration values can give hints to parameters in the friction terms of commonly used numerical avalanche models. The derived retarding accelerations imply a behavior different to the one proposed in those models. They also indicate a dependency of the retarding acceleration on the stage of the flow. (C) 2007 Elsevier B.V. All rights reserved.