Geophysical flow dynamics using pulsed Doppler radar

使用脉冲多普勒雷达的地球物理流动力学

基本信息

批准号：
NE/F00415X/1
负责人：
Christopher Keylock
金额：
$ 2.74万
依托单位：
University of Leeds
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2008
资助国家：
英国
起止时间：
2008 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FF00415X%2F1
关键词：
Geophysical flow dynamics using pulsed

项目摘要

Mass movement flows are a significant natural hazard throughout the world and yet our ability to predict their behaviour and plan for their effects is limited, in part, by our lack of understanding of their flow dynamics. This research will investigate the dynamics of geophysical mass movement flow processes (specifically snow avalanches and pyroclastic flows) by means of carefully-controlled trials at avalanche and volcano test sites. This research will utilise a sophisticated and new Doppler radar imaging instrument, able to form two-dimensional animated images of a variety of geophysical events. This radar has been under development at University College London, supported by the Royal Society, and permits imaging of the dense parts of the flow (often the most important component for risk analyses) by penetrating the suspended matter surrounding snow avalanches and pyroclastic flows. Advanced signal processing algorithms will be used to generate detailed models of the structure and dynamics of the flow. At present, opto-electronic instruments can provide such information at a single point and existing Doppler radar can provide crude images of the flow speed, but averaged over 50 m and only giving an overall measure of the velocity magnitude (with no information on direction). Our instrument will reduce the averaging distance to just 1 m so that, for the first time, information on individual blocks in the flow can be obtained and assessed in relation to their significance for the overall flow dynamics. Thus, we can assess the validity of a variety of flow laws that have been proposed for describing such processes. This will lead to improved models for these flow processes by limiting the values of coefficient in the models to reasonable values and rejecting some proposed flow laws outright. This will lead to more accurate modelling of these processes, which in turn will improve risk analyses and the design of defensive structures. This study will therefore considerably increase our understanding of flow movement and raise the status of UK research in this area to internationally-leading standards.

大众运动流是全世界的重要自然危害，但是我们预测其行为和计划影响的能力部分是有限的，部分原因是我们对他们的流动动态缺乏理解。这项研究将通过在雪崩和火山测试地点进行了精心控制的试验来研究地球物理质量运动流动过程（特别是雪雪崩和火山碎屑流）的动力学。这项研究将利用一种复杂的新多普勒雷达成像仪器，能够形成各种地球物理事件的二维动画图像。伦敦大学学院（University College）在皇家学会（Royal Society）的支持下正在开发这一雷达，并允许对流量的密集部分（通常是风险分析的最重要组成部分）进行成像，通过穿透周围的雪地雪崩和火山碎屑流的悬浮物。高级信号处理算法将用于生成流动结构和动力学的详细模型。目前，光电器仪器可以在一个点提供此类信息，现有的多普勒雷达可以提供流速的粗略图像，但平均超过50 m，并且仅提供速度幅度的整体度量（没有方向的信息）。我们的仪器将将平均距离降低到仅1 m，因此，就可以获得有关流动中各个块的信息，并就其对整体流动动力学的意义进行了评估。因此，我们可以评估已提出描述此类过程的各种流量定律的有效性。这将通过将模型中的系数值限制为合理的值并直接拒绝某些提出的流动法则，从而导致这些流动过程的改进模型。这将导致对这些过程进行更准确的建模，从而改善风险分析和防御结构的设计。因此，这项研究将大大提高我们对流动运动的理解，并提高英国在这一领域的研究状况达到国际领先的标准。