|Tesis Doctorales de la Universidad de Alcalá
|LIMITS OF PERFORMANCE OF CHIRPED- PULSE PHASE-SENSITIVE OTDR|
|Autor/a||Pereira Da Costa, Luis Duarte|
|Director/a||González Herráez, Miguel|
|Codirector/a||Fernández Ruiz, María del Rosario|
|Fecha de defensa||11/12/2020|
|Calificación||Sobresaliente Cum Laude|
|Programa||Electrónica: Sistemas Electrónicos Avanzados. Sistemas Inteligentes (RD 99/2011)|
|Resumen||Distributed acoustic sensing is an emerging field of research which aims to develop methods capable of using a single optical fiber as a long, dense, and high-sensitivity sensor array. Currently, the most promising implementations measure the interference of Rayleigh backscattered light, obtained by probing the fiber with light from a source of high coherence.
These methods are known as Phase-sensitive Optical Time-Domain Reflectometers (¿OTDR), and are currently undergoing a period of active research and development, both academically and industrially. One of its variants, known as the Chirped-Pulse ¿OTDR (CP-¿OTDR), was developed in 2016. This technique has proven to be remarkably sensitive to strain and temperature, with an attractively simple implementation.
In this thesis, we delve into the intricacies of this technique, probing its fundamental limits and addressing current limitations. We discuss the implications of estimation on the performance statistics, the impact of different noise sources and the origin of cross-talk between independent measured positions. In doing so, we also propose methods to reach the current fundamental limitations, and overcome the upper bound of measurable perturbations.
We then demonstrate new potential applications of the technique: in seismology, by exploiting the high spatial density of measurements for array signal processing; in the fast characterization of linear birefringence in standard single-mode fibers; and on the measurement of sound pressure waves, by using a special flat cable structure to embed the fiber under test.
Finally, we summarize and comment on the aforementioned achievements, proposing some open lines of research that may originate from these results|