UnderTracker: Underground Animal Tracking and Mapping in 3D

自从2002年具有开创性意义的ZebraNet项目使用移动节点监测斑马以来，使用无线传感器网络进行野生动物跟踪已经获得了大量的关注和研究。然而，到目前为止，研究一直集中在监测动物在地面上的时候。目前，当动物在地下时，不可能自动监控它们。造成这种情况的主要原因是无线电波被土层严重衰减，以至于无法使用。为了更好地了解洞穴动物的行为和习性，迫切需要一种系统，当它们在洞穴或隧道内时，可以对它们进行定位。欧洲獾就是一个最好的例子--在英国，獾是受保护的物种，但由于它们可能与牛结核病有关，因此受到广泛的扑杀。通过监测内部环境条件和地下动物的相互作用，可能会更好地了解感染情况。为了解决这些问题，我建议使用低频磁场(即磁感应原理，MI)，它能够穿透土壤而不衰减，为野生动物在洞穴内提供超低功率的三维定位。当动物在地面上时，来自跟踪项圈的数据将通过传统的高频无线电链路转发，这意味着不需要重新捕获动物来获取存储的信息。通过绘制动物随时间移动的地图，地下隧道结构本身将被确定，目前只能通过挖掘破坏性地获得这些东西。隧道内的传感器将监测气体浓度和温度梯度，这将有助于解释动物如何在地下实现适当的通风并保持体温。为了调查动物的行为，跟踪项圈将配备微型传感器，如加速计和磁力计，这些传感器将记录运动和能量。为了减少数据量，跟踪项圈将自动表征动物行为基元，如行走或睡眠。为了进一步提高这些信息的学习速度，跟踪项圈将共享运动特征，形成一个分布式知识库。因此，这项研究提出了一个广泛的动物监测和跟踪系统，将首次揭示地下动物生活的完整图景。为了实现这项研究的目标，将与牛津大学野生动物保护研究单位建立密切合作。他们将指导跟踪项圈的设计，并在牛津郡威瑟姆森林进行的定期研究中将它们连接到合适的獾身上。他们的专业知识在构建这项研究以解决与生物学相关的问题方面也至关重要。来自该系统的数据也将被剑桥大学计算实验室的研究人员用来调查社交网络。最终，这种对獾生活细节的洞察将有助于揭开它们相互作用的真实程度，不仅有助于揭示该物种的行为生态，还将研究它们的社会制度，并解决有关疾病传播的重要问题。

Wildlife tracking using wireless sensor networks has garnered a great deal of attention and research, since the seminal ZebraNet project monitored zebras with mobile nodes in 2002. However, research to date has concentrated on monitoring animals when they are above ground. It is currently impossible to automatically monitor animals whilst they are underground. The main reason for this is that radio waves are severely attenuated by layers of soil, to the point of being unusable. There is a strong need for a system that can localize burrowing animals when they are within their dens or tunnels, in order to better understand their behaviour and habits. A prime example of this is the European badger - badgers are a protected species in the UK, yet are subject to widespread culling due to their possible link to bovine TB. By monitoring internal sett conditions and animal interactions underground, a better understanding of infection could potentially be obtained. To tackle these issues, I propose the use of low frequency magnetic fields (i.e. the principle of magneto-induction, MI), which are able to penetrate soil without attenuation, to provide ultra-low power three dimensional localization of wild animals within their burrows. Data from tracking collars will be forwarded by conventional high frequency radio links when the animal is above ground, meaning that the animal does not need to be recaptured to obtain the stored information. By mapping animal movements over time, the subterranean tunnel architecture itself will be determined, something which can currently only be obtained, destructively, through excavation. Sensors within the tunnel will monitor gas concentrations and temperature gradients, which will help to explain how animals achieve suitable ventilation underground and maintain body temperature. To investigate animal behaviour, tracking collars will be equipped with miniature sensors, such as accelerometers and magnetometers, which will record motion and energetics. To reduce data volumes, tracking collars will automatically characterize animal behaviour primitives, such as walking or sleeping. To further increase the rate of learning this information, tracking collars will share motion features, forming a distributed knowledge base. Thus, this research proposes a broad animal monitoring and tracking system, which will reveal a complete picture of animal life underground, for the first time.To achieve the goals of the research a close collaboration with the Wildlife Conservation Research Unit at the University of Oxford will be formed. They will guide the design of the tracking collars and attach them to suitable badgers during regular research undertaken in Wytham Woods, Oxfordshire. Their expertise is also vital in framing the research to address biologically relevant questions. Data from this system will also be used by researchers in the University of Cambridge Computing Laboratory, to investigate social contact networks. Ultimately this insight into the detail of badgers' lives will help to unravel the true extent with which they interact with each other, and shed light not just on the behavioural-ecology of this species, but investigate their social systems and address important questions concerning the transmission of disease.