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.

该博士学位的总体目标是开发毫米波雷达在地球科学中的应用，重点关注火山-冰川和冰-海洋的常规相互作用。毫米波雷达在绘制地形图方面比光学测量方法具有关键优势。圣安德鲁斯大学由 Macfarlane 和 Robertson 开发的用于火山成像的 AVTIS 雷达具有高分辨率，同时在能见度较低的条件下工作 [1] 已经证明了此类仪器通过完全遮挡来绘制火山地形变化的潜力。 （例如火山灰、云）除了地形之外，毫米波雷达还可以测量移动目标的反射率和速度，包括 DEM 提取的高时空分辨率绘图以及基于反射率或标准化的地形类型区分。雷达截面（NRCS）将被开发和完善，以改进不同地形表面类型的分类，这些对于火山-冰川相互作用和相关灾害的研究至关重要，但人们对此仍知之甚少（例如，火山-冰川相互作用和相关灾害）。 2010 年埃亚菲亚德拉冰盖喷发），因为喷发期间的活动关键时期经常被掩盖，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、强度或融水引起的质量运动，例如火山泥流。 - 火山顶（例如冰岛）。冰川和冰盖边缘的冰山崩解。对于我们了解格陵兰冰盖在不久的将来对海平面上升的贡献至关重要，因此需要在浓云覆盖和降水的情况下持续监测接地冰缘，其中采用传统技术（激光雷达和延时摄影）。因此，毫米波雷达在这些条件下生成 DEM 的能力将是非常宝贵的，因此该项目的第二阶段将是使用 AVTIS-2 雷达进行冰川测绘，这在该项目中从未有过报道。大致遵循以下结构： - 使用现有的 AVTIS 数据开发改进的 DEM 提取方法 首先使用来自当地采石场同步调查的 LIDAR 数据作为地面实况，将研究和完善从 AVTIS 雷达数据传感体积中提取 DEM 表面的方法。这些新方法将根据现有的 AVTIS 数据集（主要来自蒙特塞拉特苏弗里埃尔山火山的数据）进行评估 - 也可以在本地获取用于算法开发的其他数据 - 基于现有的分析开发地形分类算法。 AVTIS 数据和粗糙表面散射模型，在广泛的 AVTIS 数据集上进行了测试，其中包括火山地形和本地采集的数据，例如 Rest and Be Thanhful、Argyll；Old Man of Storr、Skye - 收集毫米波 NRCS 数据。使用 AVTIS-2 雷达进行野外活动，将冰川冰作为入射角的函数，并开发适合雷达性能预测的经验模型 - 收集第一个数据。使用 AVTIS-2 测量冰川的毫米波雷达 DEM，并与同时采集的激光雷达（地面激光扫描）DEM 进行定量比较 - 探索该仪器在火山-冰和冰-海洋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.、Pinkerton, H. 和 Wadge, G.， “使用 AVTIS 地面 94GHz 双模雷达/辐射成像仪绘制火山地形图”，IEEE Trans. Sens.，51，(1)，2013 年，第 455 - 472 页。