This paper suggests a transform relation in Brillouin Optical Time Domain Analyzer (BOTDA). By computerized signal processing using the relationship, the spatial resolution of BOTDA can be improved to sub millimeter order theoretically, compares to about 1m of present art of view.
Xin-Zen Li, Xin-Zen Li,
"A new technique for fine spatial resolution BOTDA", Proc. SPIE 4185, Fourteenth International Conference on Optical Fiber Sensors, 418544 (9 November 2000); doi: 10.1117/12.2302291; https://doi.org/10.1117/12.2302291