A lateral locating method for optical fiber distributed intrusion sensing system

A lateral locating method is proposed and demonstrated in optical fiber distributed vibration sensing system based on phase-sensitive optical time domain reflectometer. The locating depends on a method of time difference of arrival to calculate the time difference between two sensing points. Through this method, we can get the vertical distance between the vibration source and the sensing fiber. Therefore, we can make sure the degree of danger of intrusion. The test results show that the locating accuracy is about 2.10 m with 100-MHz sampling rate, 1-kHz pulse repetition rate, and 1500 sampling points within one pulse interval.