Collaborative Research: EAGER: A Dual-Band Radar for Measuring Internal Ice Deformation: a Multipass Ice-Penetrating Radar Experiment on Thwaites Glacier and the McMurdo Ice Shelf

合作研究：EAGER：用于测量内部冰变形的双波段雷达：在思韦茨冰川和麦克默多冰架上进行的多通道穿冰雷达实验

• 批准号: 2027579
• 负责人: Knut Christianson
• 金额: $ 8.19万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-15 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2027579&HistoricalAwards=false
• 关键词: Collaborative; Research; EAGER; Dual; Band

This project will develop a new ice-penetrating radar system that can simultaneously map glacier geometry and glacier flow along repeat profiles. Forecasting an ice-sheet’s contribution to sea level requires an estimate for the initial ice-sheet geometry and the parameters that govern ice flow and slip across bedrock. Existing ice-sheet models cannot independently determine this information from conventional observations of ice-surface velocities and glacier geometry. This introduces substantial uncertainty into simulations of past and future ice-sheet behavior. Thus, this new radar capability is conceived to provide the needed data to support higher-fidelity simulations of past and future ice-sheet behavior and more accurate projections of future sea level.The new radar system will integrate two existing radars (the multi-channel coherent radio-echo depth sounder and the accumulation radar) developed by the Center for the Remote Sensing of Ice Sheets, as well as adding new capabilities. An eight-element very high frequency (VHF; 140-215 MHz) array will have sufficient cross-track aperture to swath map internal layers and the ice-sheet base in three dimensions. A single ultra high frequency (UHF; 600-900 MHz) antenna will have the range and phase resolution to map internal layer displacement with 0.25-mm precision. The VHF array will create 3D mappings of layer geometry that enable measurements of vertical velocities by accounting for spatial offsets between repeat profiles and changing surface conditions. The vertical displacement measurement will then be made by determining the difference in radar phase response recorded by the UHF antenna for radar profiles collected at the same locations at different times. The UHF antenna will be dual-polarized and thus capable of isolating both components of complex internal reflections. This should enable inferences of ice crystal orientation fabric and widespread mapping of ice viscosity. Initial field testing of the radar will occur on the McMurdo Ice Shelf and then progress to Thwaites Glacier, Antarctica. The dual-band radar system technology and processing algorithms will be developed with versatile extensible hardware and user-friendly software so that this system will serve as a prototype for a future community radar system.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目将开发一个新的冰渗透雷达系统，该系统可以轻松地沿重复轮廓绘制冰川几何形状和冰川流量。预测冰淇淋对海平面的贡献需要估算初始冰盖几何形状以及控制冰流并在基岩上滑动的参数。现有的冰盖模型无法独立地从传统的冰面速度和冰川几何形状的观察结果中确定这些信息。这引入了对过去和未来冰盖行为的模拟中的实质性不确定性。这种新的雷达能力被构想为提供所需的数据，以支持对过去和未来的冰单行为的高保真模拟以及对未来海平面的更准确的预测。新雷达系统将整合两个现有的雷达（由远程感应的冰上感应的冰上的雷达（多通道相干电动通道驱动器和累积雷达），并添加了新的Cabab，以及添加了新的Cabab。一个非常高的频率（VHF; 140-215 MHz）阵列将具有足够的跨轨道孔径，以绘制三个维度的内部层和冰盖基底座。单个超高频（UHF; 600-900 MHz）天线将具有范围和相位分辨率，以0.25毫米的精度绘制内部层位移。 VHF阵列将创建层几何形状的3D映射，通过考虑重复轮廓和变化的表面条件之间的空间偏移来实现垂直速度的测量。然后，将通过确定UHF天线记录的雷达相响应的差异来进行垂直位移测量，以在不同时间在相同位置收集的雷达轮廓。 UHF天线将被双偏振，因此能够分离复杂内部反射的两个组成部分。这应该可以推断出冰晶方向织物以及冰粘度的宽度映射。雷达的初始现场测试将发生在McMurdo冰架上，然后前进到南极的Thwaites冰川。双波段雷达系统技术和处理算法将使用多功能的可扩展硬件和用户友好的软件开发，以便该系统成为未来社区雷达系统的原型。该奖项反映了NSF的法定任务，并通过评估该基金会的知识分子功能和广泛的影响来评估NSF的法定任务。