Development of a fibre optic distributed acoustic sensor

Fibre optic Distributed Acoustic Sensor (DAS) is a particular sensor which offers the possibility of measuring at thousands of points simultaneously only using, as sensing mean, the normal optical fibre. In this thesis an implementation of this distributed sensing system is presented, also exploiting the so called ϕ-OTDR. With this technology is possible to sense both static and dynamic events such as time varying-signals, vibrations, crack of the bridges