Position determination and monitoring of disturbance along distributed fiber optic sensors

Distributed Fiber Optic Sensor for Position Determination is a novel position sensor and can be used as a monitoring system in communication main of long distances. Single fiber is employed as the sensor in the system to pick up the disturbances in the environment. The principle of the system is that for a disturbance signal applied at a particular position along the fiber, the response, in the frequency domain, presents a series of periodic maxima and minima (or nulls). These minima depend on the position of the disturbance along a fiber. An intelligent, reliable and real-time signal processing method is needed in such a system to determine the position of disturbance. It is not enough to process the signal of the system just using FFT (fast Fourier transform) algorithm. By using power spectral estimation and wavelet transforming as the method of signal processing, the position of a random disturbance is successfully determined.