From the physics to the field, using Rayleigh, Brillouin, and Raman fiber optic distributed sensing for condition and environment monitoring

Fiber distributed sensing based on Rayleigh, Brillouin or Raman backscattering is just over 40 years old. However, it took almost half of that time to transform physical concepts into measuring instruments and another 10 years to achieve permanent and reliable deployment in the field. Through this lengthy but classical process, Rayleigh, Brillouin and Raman became Distributed Acoustic Sensing (DAS), Distributed Temperature Sensing (DTS) or Distributed Strain Sensing (DSS), standards were written, and multiple software tools were developed to handle the ever-growing amount of measured data. In this paper, we first illustrate some of the fundamental steps required to go from the physics to the interrogators, in particular the importance of standardization with the associated common language and reference tests. Then we describe how to move from the interrogator to the field with the use of fully automated, reliable and self-diagnosed interrogators, including the needs for communication and data management. Eventually, we show how to obtain meaningful data from the field through recent deployment examples in the power cable industry, together with some of the typical software tools.