The distributed Brillouin sensing technique has been developed rapidly since its first demonstration three decades ago. Numerous investigations on the performance enhancement of Brillouin sensors in respect to spatial resolution, sensing range, and measurement time have paved the way to its industrial and commercial applications. This chapter provides an overview of different Brillouin sensing techniques and mainly focuses on the most widely used one, the Brillouin optical time domain analysis (BOTDA). The history and the development of Brillouin sensing regarding the performance enhancement in various methods and their records will be reviewed, commented, and compared with each other. As well, related sensing errors and limitations will be discussed, together with the corresponding strategies to avoid them.
Part of the book: Fiber Optic Sensing