MAPPING THE UNDERWORLD: MULTI-SENSOR DEVICE CREATION, ASSESSMENT, PROTOCOLS

该项目旨在通过结合新型探地雷达、声学和低频主动和被动电磁场（称为准静态场）方法，为地下公用设施的定位创建一个多传感器设备原型，并进行基础研究。该多传感器装置将同时采用地面探测和管道内探测的能力，以实现迄今为止不可能实现的目标，即在不进行局部验证挖掘的情况下检测每个公用设施。例如，在探地雷达（GPR）的情况下，传统上从地面部署时，它在饱和粘土中的穿透深度严重有限，将GPR发射器定位在深埋管道（例如下水道）中，而将接收器部署在地面上，其优点是信号只需要通过土壤单向传播。从而克服了传统的表面向下技术（依赖于通过复杂表面结构和土壤的双向旅行）的严重信号衰减和深度估计问题。准静态场解决方案利用高压电缆的50Hz泄漏电流和地球电磁场来照亮地下基础设施。MTU可行性研究表明，这些技术具有相当大的潜力，特别是在探测难以发现的盆端电缆、光纤电缆、服务连接和其他浅层、小直径服务方面。多传感器装置的第三个关键技术是声学，它在饱和粘土中效果最好，而在饱和粘土中，探地雷达传统上是有问题的。声学技术可以用于定位传统上难以识别的服务（如塑料管），方法是从远程位置向管壁或管壁内馈送微弱的声学信号。在多传感器设备中，这些技术与优化组合输出的智能数据融合的结合是全新的，旨在实现100%的定位成功率而不干扰地面（迄今为止，这是一项不可能完成的任务，也是国际上的“圣杯”）。通过对土壤中信号传输和衰减模型的详细研究，增强了上述技术，使这些技术能够智能地适应不同的地面条件，从而使结果产生阶梯式的改进。这些发现将与现有的浅层表层土壤相结合，并通过与英国地质学会（BGS）合作制作地面3D地图，以证明为不同技术创建英国范围内的地球物理属性地图的概念。这将使该设备的用户能够根据任何地点的特定地面条件做出最合适的操作参数的明智选择，并为解释结果数据提供基本参数，并消除此类技术定位精度中固有的不确定性。最后，我们还将探索知识引导的解释，使用从DTI（BERR）资助的项目VISTA中生成的综合公用事业数据库中获得的信息。

The project aims to create a prototype multi-sensor device, and undertake fundamental enabling research, for the location of underground utilities by combining novel ground penetrating radar, acoustics and low frequency active and passive electromagnetic field (termed quasi-static field) approaches. The multi-sensor device is to employ simultaneously surface-down and in-pipe capabilities in an attempt to achieve the heretofore impossible aim of detecting every utility without local proving excavations. For example, in the case of ground penetrating radar (GPR), which has a severely limited penetration depth in saturated clay soils when deployed traditionally from the surface, locating the GPR transmitter within a deeply-buried pipe (e.g. a sewer) while the receiver is deployed on the surface has the advantage that the signal only needs to travel through the soil one way, thereby overcoming the severe signal attenuation and depth estimation problems of the traditional surface-down technique (which relies on two-way travel through complex surface structures as well as the soil). The quasi-static field solutions employ both the 50Hz leakage current from high voltage cables as well as the earth's electromagnetic field to illuminate the underground infrastructure. The MTU feasibility study showed that these technologies have considerable potential, especially in detecting difficult-to-find pot-ended cables, optical fibre cables, service connections and other shallow, small diameter services. The third essential technology in the multi-sensor device is acoustics, which works best in saturated clays where GPR is traditionally problematic. Acoustic technology can be deployed to locate services that have traditionally been difficult to discern (such as plastic pipes) by feeding a weak acoustic signal into the pipe wall or its contents from a remote location. The combination of these technologies, together with intelligent data fusion that optimises the combined output, in a multi-sensor device is entirely novel and aims to achieve a 100% location success rate without disturbing the ground (heretofore an impossible task and the 'holy grail' internationally).The above technologies are augmented by detailed research into models of signal transmission and attenuation in soils to enable the technologies to be intelligently attuned to different ground conditions, thereby producing a step-change improvement in the results. These findings will be combined with existing shallow surface soil and made ground 3D maps via collaboration with the British Geological Society (BGS) to prove the concept of creating UK-wide geophysical property maps for the different technologies. This would allow the users of the device to make educated choices of the most suitable operating parameters for the specific ground conditions in any location, as well as providing essential parameters for interpretation of the resulting data and removing uncertainties inherent in the locating accuracy of such technologies. Finally, we will also explore knowledge-guided interpretation, using information obtained from integrated utility databases being generated in the DTI(BERR)-funded project VISTA.