The application of millimetre wave radar to the study of volcano-glacier interactions and ice-ocean interactions in conditions of reduced visibility.

毫米波雷达在能见度降低条件下火山-冰川相互作用和冰-海洋相互作用研究中的应用。

• 批准号: 2093489
• 金额: --
• 依托单位: University of St Andrews
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2093489
• 关键词: application; millimetre; wave; radar; study

The overall aim of this PhD is to develop the use of millimetre wave radar for applications in geosciences, focusing on volcano-glacier and ice-ocean interactions. Millimetre wave radar offers a key advantage over conventional optical survey methods in its ability to map terrain with high resolution whilst operating in conditions of reduced visibility. The AVTIS radars developed at University of St Andrews by Macfarlane & Robertson for volcano imaging [1] have demonstrated the potential for such instruments to map topographic change on volcanoes through complete obscuration (e.g. ash, clouds). In addition to topography, the millimetre wave radar can measure reflectivity and the velocity of moving targets, including high spatio-temporal resolution mapping of rainfall. DEM extraction and the discrimination between terrain types based on reflectivity, or normalised radar cross section (NRCS), will be developed and refined for improved classification of different terrain surface types. These are central to the study of volcano-glacier interactions and related hazards, which are still poorly understood (e.g. the 2010 Eyjafjallajökull eruption) as critical periods of activity during eruptions are often obscured. The AVTIS radar will elucidate changes in the volcano and glacier geometries, impacting eruption timing, magnitude or meltwater-induced mass movements e.g. lahars. The first case study will thus target ice-capped volcanoes (e.g. Iceland). The calving of icebergs at the margins of glaciers and ice sheets is critical to our understanding of the near future contribution of the Greenland Ice Sheet to sea level rise. Continuous monitoring of grounded ice margins under conditions of heavy cloud cover and precipitation is thus needed, where conventional techniques (LIDAR and time lapse photography) are rendered useless. The ability of the millimetre wave radar to generate DEMs under these conditions will be invaluable. The second stage of the project will thus be glacier mapping with the AVTIS-2 radar, which has never previously been reported in the literature. The project will follow broadly this structure: - Develop improved DEM extraction methodology using existing AVTIS data. Initially using LIDAR data from a coincident survey of a local quarry as ground truth, methods for DEM surface extraction from the AVTIS radar data sensing volume will be investigated and refined. These new methods will be evaluated against existing AVTIS datasets (mainly data from the Soufriere Hills Volcano, Montserrat). Additional data for algorithm development can also be acquired locally. - Develop terrain classification algorithms based on analysis of existing AVTIS data and rough surface scattering models, tested on the extensive AVTIS data set, which already includes volcanic terrain and locally acquired data e.g. Rest and Be Thankful, Argyll; Lomond Hills Fife; Old Man of Storr, Skye. - Gather millimetre wave NRCS data of glacier ice as function of incidence angle using the AVTIS-2 radar on field campaign to e.g. Iceland and develop an empirical model suitable for radar performance prediction. - Collect the first mm-wave radar DEMs of glaciers using AVTIS-2 and quantitatively compare with contemporaneously acquired lidar (terrestrial laser scanned) DEMs. - Explore the new interpretational potential of the instrument in terms of volcano-ice and ice-ocean interactions [1] Macfarlane, D.G., Odbert, H.M., Robertson, D.A., James, M.R., Pinkerton, H. & Wadge, G., "Topographic and thermal mapping of volcanic terrain using the AVTIS ground based 94GHz dual-mode radar/radiometric imager", IEEE Trans. Geosci. Rem. Sens., 51, (1), 2013, pp. 455 - 472.

该博士的总体目的是开发用于地球科学应用毫米波雷达的使用，重点是火山 - 冰川和冰山相互作用。毫米波雷达比常规光学调查方法具有关键的优势，其在可见性降低的条件下以高分辨率绘制地形的能力。 MacFarlane＆Robertson在圣安德鲁斯大学开发的AVTI雷达[1]证明了此类工具通过完整观察（例如灰烬，云）来绘制火山上的地形变化的潜力。除地形外，毫米波雷达还可以测量反射率和移动目标的速度，包括降雨的高时空分辨率映射。 DEM提取和基于反射率或归一化雷达横截面（NRC）的地形类型之间的歧视将开发并完善，以改善不同地形表面类型的分类。这些是研究火山 - 冰川相互作用和相关危害的核心，因为这在喷发过程中的关键活动期间通常被掩盖了，这些危害仍然很少了解。 AVTIS雷达将阐明火山和冰川几何形状的变化，从而影响喷发时间，幅度或融合水引起的质量运动，例如拉哈尔人。因此，第一个案例研究将针对冰盖的火山（例如冰岛）。在冰川和冰盖边缘的冰山产犊对于我们对格陵兰冰盖对海平面上升的不久的将来的贡献至关重要。因此，在沉重的云层和降水条件下，需要连续监测接地的冰缘，如果传统技术（LiDar和Timapse Photography）变得毫无用处。毫米波雷达在这些条件下产生DEM的能力是无价的。因此，该项目的第二阶段将是使用AVTIS-2雷达冰川映射的，该雷达以前从未在文献中报道过。该项目将广泛遵循此结构： - 使用现有的AVTI数据来开发改进的DEM提取方法。最初，将研究和完善从AVTIS雷达数据传感量中进行DEM表面提取的方法来使用局部采石场的同时调查的LIDAR数据。这些新方法将针对现有的AVTIS数据集进行评估（主要来自Montserrat Soufriere Hills火山的数据）。算法开发的其他数据也可以在本地获取。 - 根据对现有的AVTI数据和粗糙的表面散射模型的分析，开发地形分类算法，该模型对广泛的AVTIS数据集进行了测试，该数据集已经包括火山地形和本地获得的数据，例如。休息并感恩，阿盖尔； Lomond Hills Fife；斯塔尔的老人。 - 收集冰川冰的毫米波NRCS数据作为入射角的函数，使用AVTIS-2雷达在现场运动中进行，例如冰岛并开发适合雷达性能预测的经验模型。 - 使用AVTIS-2收集冰川的第一个MM波雷达Dem，并定量与同时获得的LiDAR（陆地激光扫描）Dem进行了比较。 - 探索工具在火山冰和冰山相互作用方面的新解释潜力[1] Macfarlane，D.G.，Odbert，H.M.，Robertson，D.A.，James，M.R.反式。 Geosci。 REM。 Sens。，51，（1），2013年，第455-472页。