Double-Ended Calibration of Fiber-Optic Raman Spectra Distributed Temperature Sensing Data

Over the past five years, Distributed Temperature Sensing (DTS) along fiber optic cables using Raman backscattering has become an important tool in the environmental sciences. Many environmental applications of DTS demand very accurate temperature measurements, with typical RMSE < 0.1 K. The aim of this paper is to describe and clarify the advantages and disadvantages of double-ended calibration to achieve such accuracy under field conditions. By measuring backscatter from both ends of the fiber optic cable, one can redress the effects of differential attenuation, as caused by bends, splices, and connectors. The methodological principles behind the double-ended calibration are presented, together with a set of practical considerations for field deployment. The results from a field experiment are presented, which show that with double-ended calibration good accuracies can be attained in the field.

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在过去五年中，利用拉曼反散射技术在光纤电缆上实现的分布式温度传感（DTS）已成为环境科学领域的一项重要工具。众多环境应用对DTS的温度测量精度提出了极高的要求，典型的均方根误差（RMSE）需小于0.1开尔文。本论文旨在描述并阐明在野外条件下，为达到如此精度所采用的双端校准方法的优势与不足。通过测量光纤电缆两端的反散射，可以纠正由弯曲、接头和连接器引起的微分衰减效应。双端校准的方法论原则被提出，同时伴随一系列适用于野外部署的实际考虑因素。一项野外实验的结果被展示，该结果表明，在双端校准下，野外测量可以实现良好的精度。原始项目数据可通过联系 [e-mail] 获取。