Development of GPS as a Volcanic Plume Sensor

1360810larson这笔拨款支持代码的开发，希望能够使用安装在世界各地活火山系统附近（例如，阿留申群岛，冰岛）的现有全球导航卫星系统（GNSS）接收器，实现可靠、自动化、远程探测喷发的火山灰和气体羽流。目前在世界各地安装的大多数连续运行的GNSS接收器用于探测和量化由构造、地震、火山、地表载荷或地下流体动力学（地球的强迫变形）引起的细微（mm）或不那么细微(m)的位置变化。地壳。在对已知有喷发火山灰云活动记录的火山附近站点的GNSS信噪比观测结果的初步分析中，PI证明了该技术用于探测羽流的可行性。该项目将进一步开发和测试算法，利用GPS信号强度数据自动探测火山羽流，并将依靠多年来从数百个地点采集的GNSS数据来建立检索的精度。这些站点将包括来自不同制造商的美国GPS和俄罗斯GLONASS卫星接收器。研究结果将通过对阿拉斯加和冰岛火山羽流的扫描雷达观测来验证。不同接收器的性能将被分类，以向寻求实施GPS羽流传感网络的火山科学家提供反馈。除了开发GNSS探测火山灰羽流的代码外，该项目还将涉及GPS数据的正演建模，试图将GPS信号强度观测与火山灰浓度和颗粒大小联系起来。考虑到多个GNSS网络在全球范围内运行，有许多接近活跃的火山系统，在工具包中以边际成本检测危险火山灰羽流的另一种观测方式对保护生命和财产有影响，对减轻航空公司的危害特别有意义。***

1360810LarsonThis grant supports development of code that hopes to allow for reliable, automated, remote detection of plumes of erupted volcanic ash and gas using extant global navigation satellite system (GNSS) receivers installed at locations around the world that are proximal to active volcanic systems (e.g., the Aleutians, Iceland). Most extant continuously operating GNSS receivers that have been installed around the world are used for detection and quantification of subtle (mm) or not so subtle (m) position changes caused by tectonically, seismically, volcanically, surface load or subsurface fluid dynamics-forced deformation of the Earth? crust. In preliminary analyses of GNSS signal to noise ratio observations at stations proximal to volcanoes with a known record of eruptive ash cloud activity, the PI has demonstrated the feasibility of the technique for detection of plumes. This project will further develop and test algorithms to automatically detect volcanic plumes using GPS signal strength data and will rely on GNSS data taken from hundreds of sites over multiple years to establish the precision of retrievals. The sites will include U.S. GPS and Russian GLONASS capable satellite receivers from various manufacturers. The results will be validated against scanning radar observations of volcanic plumes in Alaska and Iceland. The performance of different receivers will be catalogued to provide feedback to volcano scientists seeking to implement GPS plume sensing networks. In addition to developing code for GNSS detection of volcanic ash plumes, the project will involve forward modeling of GPS data in an attempt to link GPS signal strength observations to ash concentrations and particle size.Having another observational modality in the toolkit for detection of hazardous volcanic ash plumes at marginal cost, given that multiple GNSS networks are operating around the globe with many proximal to active volcanic systems, has implications for the protection of life and property and is of particular interest to mitigating airline hazards.***