Performance Enhancement in Distributed Fiber Sensing by Noise Reduction

作为工业4.0和智慧城市的关键推动因素，物联网（IoT）预计到2020年将拥有超过7万亿美元的市场，连接近300亿台设备。传感器占连接设备的大量，并作为物联网的基本支柱。光纤传感一直是物联网的驱动力，主要是由于光纤的独特特性，即尺寸小，化学惰性，不受电磁干扰。此外，分布式光纤传感器（DFS）由于其每个传感点的低成本而提供了经济的解决方案。DFS的性能由传感系统的信噪比（SNR）定义。 目前的研究主要集中在信号增强，以提高信噪比。所报道的方法通常需要昂贵且耗电的设备。此外，SNR改善的进展似乎不足以满足物联网的快速发展和部署。与波罗的海下德国和俄罗斯之间的1，222 km管道长度（北溪2号项目）或仅在德国的500，000 km天然气网络相比，当前没有内联放大的DFS的有限感测距离（通常< 100 km）远远不够。为了满足对出色的分布式传感性能（特别是长距离）的需求，该提案旨在通过降低噪声从另一个方向显着提高SNR。通过对分布式传感中不同噪声源的起源的基本理解，该提案的主要目标是研究不同的方法来降低噪声并提高传感器的性能。如果实现这一目标，SNR可以以更具成本效益和能源效率的方式提高至少四个数量级，使最先进的传感器的性能翻一番。

As a key enabling factor for Industry 4.0 and smart city, the Internet of things (IoT) is forecasted to have a market over $ 7,000 billion and connect nearly 30 billion devices by 2020. Sensors account for a large number of the connected devices and act as a fundamental pillar of IoT. Optical fiber sensing has been a driving force for the IoT, mainly due to the unique properties of the optical fiber, i.e. being small size, chemically inert, and immune to electromagnetic interference. Furthermore, distributed fiber sensors (DFSs) offer economic solutions due to their low-cost per sensing points. The performance of DFS is defined by the signal-to-noise ratio (SNR) of the sensing system. Current research focuses on signal enhancement to improve the SNR. The reported methods often need costly and power-consuming equipment. Furthermore, the progress of the SNR improvement seems to be insufficient for the fast development and deployment of IoT. The limited sensing distance of current DFSs (usually < 100 km) without inline amplification, is far from enough, compared with the 1,222 km pipeline length under the Baltic Sea between Germany and Russia (North Stream 2 project) or the 500,000 km gas network just in Germany. To answer to the need for excellent distributed sensing performance particularly over long distances, the proposal ambitions to significantly enhance the SNR from the other direction—by reducing noise. By a fundamental understanding of the origin of different noise sources in distributed sensing, the main objective of the proposal is to investigate different methods to reduce the noise and to enhance the performance of the sensors. If the aim is achieved, the SNR can be enhanced by at least four orders of magnitude in a more cost-effective and energy efficient way, doubling the performance of the state-of-the-art sensors.