Enhanced buried perimeter protection using a fiber-optic target classification sensor

A buried fiber-optic target classification sensor capable of detecting and classifying human movement, human digging, machine digging, and vehicle movement was successfully tested at lengths up to 40 km for border security applications. The fiber-optic sensor was buried 2-3 feet deep in native, predominantly clay soil. Over the period of one year, the sensor was tested in a variety of environmental conditions including dry soil in the summer, wet soil after heavy rain, and frozen and snow-covered soil in the winter. At 40 km, the sensor detected and classified manual digging as well as a human walking both parallel and perpendicular to the cable. The sensor classified a machine digging test at similar to 24 km and successfully detected, classified, and tracked moving vehicles. Location-specific confidence levels for each target class were continuously updated, providing instantaneous awareness of activities over the entire range of the sensor. When an intrusion was detected and classified, it was displayed on a map with a corresponding class-specific icon. The target classification algorithm used intrusion signal patterns to detect and assign class, and was tested successfully with a high probability of detection and a low false identification rate under dynamic soil conditions typical of a long border.