Borehole location monitoring using phase-sensitive FMCW radar

热水钻探被广泛认为是在冰盖上快速、清洁地钻出深孔的最可行的方法。到目前为止，这一过程仍然被广泛地“盲目”进行，钻井人员很少或根本没有获得关于井眼深入冰中的精确轨迹的信息。这样做的负面影响，特别是当涉及到紧密分离的井眼时，在第一次尝试钻井到冰川下的Ellsworth湖（SLE）后就变得明显了。为了帮助纠正这一迫切需求，该项目的技术发展旨在实现带有源应答器的相敏调频连续波（FMCW）雷达的新应用，以厘米级精度从冰表面测量井内的空间位置，深度可达3公里。它在很大程度上建立在ApRES雷达的基础上，ApRES雷达是最近设计的，并经过了长达一年的高精度测量南极冰架基底融化率的现场验证。使用带有主动应答器的新型相敏FMCW雷达所提出的技术进行一维空间定位的概念目前处于TRL2水平，其中基本原理已被观察和报告；并且基于研究者们最近在伦敦大学学院的工作，已经形成了一个技术概念。我们现在渴望开展研究，将这一概念应用于TRL4，并在实验室和户外环境中验证3d空间定位技术。一旦实现，所提出的技术最终可能会增加未来尝试进入SLE和其他深层（约3000米）冰下环境的成功可能性，从而开辟科学探索的新途径。这种仪器的可用性也将满足BEAMISH和CryoEgg nerc资助项目的研究人员的迫切需求，他们都在寻求一种独立的方法，分别在冰床界面的特定位置和更广泛的冰下环境中获取时空数据集。拟议的仪器提供的新实验数据将提高对极地冰盖下发生的动力学的基本理解，并维持和提高英国在这些领域的研究地位，使其达到国际领先水平。

Hot-water drilling is widely accepted to be the most viable method of creating deep boreholes through ice sheets rapidly and cleanly. Up to now, this process is still widely being undertaken 'blind' with little or no information made available to the drillers about the precise trajectory that a borehole is taking as it descends deeper into the ice. The negative consequences of doing this, especially when closely separated boreholes are involved, became evident after the ill-fated first attempt at drilling into Subglacial Lake Ellsworth (SLE). To help rectify this urgent need, the technological development in this project seeks to realise a novel application of phase-sensitive frequency modulated continuous wave (FMCW) radars with an active transponder, to measure from the ice surface the spatial position inside a borehole with centimetre-precision to depths of up to 3-km. It significantly builds upon the successful ApRES radar which has been recently designed and field proven for year-long, high precision measurement of Antarctic ice shelf basal melt rates. The concept of 1D-spatial location using the proposed technique of new phase-sensitive FMCW radars with active transponders is presently at the TRL2 level, in which the basic principles have been observed and reported; and a technology concept has been formulated based on the investigators' recent work at UCL. We now aspire to carry out research to take that concept to TRL4 and validate the technology for 3D-spatial location within a laboratory and outdoor setting. Once realised, the proposed technology could ultimately increase the likelihood of success in future attempts at gaining entry into SLE and other deep (>3000-m) subglacial environments to open up new avenues of scientific exploration. The availability of such an instrument would also address the immediate needs of researchers on both the BEAMISH and CryoEgg NERC-funded projects, who are both seeking an independent method of obtaining spatio-temporal datasets at specific locations at the ice-bed interface and the broader subglacial environment, respectively. The new experimental data provided by the proposed instrument will lead to improved fundamental understanding of the dynamics occurring beneath the polar ice sheets and sustain and boost the status of UK research in these areas to internationally-leading standards.