Ordinary perimeter security systems consist of many individual sensors with detection range 200-300 meters. These limitations are connected with physical phenomena that are used in microwave and infrared barriers as well as in ground and fence cable sensors. On the contrary, fiber optic perimeter sensors can be applied in the range of many kilometers and zone length 200-300 meters is degradation of their possibilities. This paper presents investigation results of a new generation of the fiber optic perimeter sensor using WDM technique. These systems can detect a potential intruder and determine its position along a protected zone. The work presents a method of linear localization of disturbance point in the two-interferometer and modalmertic fiber optic sensors in one optical fiber. These sensors are in one fiber optic cable with two- interferometers (Sagnac) and in transmissive configuration. Using WDM technique makes it possible to obtain new technical properties that can broaden effectiveness and scope of application. Arrangement of a laboratory model of the sensors and its signal processing scheme is presented. During research of a laboratory model, it was possible to detect the position of the disturbance in one optical fiber with resolution of about 50m along a 10-km long sensor.

Date Published: 5 October 2007
PDF: 9 pages
Proc. SPIE 6736, Unmanned/Unattended Sensors and Sensor Networks IV, 67360C (5 October 2007); doi: 10.1117/12.737742

Published in SPIE Proceedings Vol. 6736:
Unmanned/Unattended Sensors and Sensor Networks IV
Edward M. Carapezza, Editor(s)