L Ine in the S And

Intrusion detection along perimeters or borders is a surveillance problem of practical value that is well suited to wireless sensor networks. The goal of the work described here is to rapidly detect, track, and classify intruders along an arbitrary or ad hoc border. We examine the requirements of border surveillance in the context of a military scenario called “Line in the Sand” or “LITS.” We explore strategies to detect and classify various intruders, develop a prototype to demonstrate our approach, and evaluate the system’s performance. Our approach is based on a distributed network of wireless sensors combined into coherent and incoherent sensor arrays that perform in situ signal processing, data aggregation, and array processing. The LITS architecture improves upon existing unattended battlefield ground sensors by eliminating both the need for hand-placement of sensors and radio repeaters, and by replacing the simple radio repeaters with integrated sensors nodes with built-in wireless microrouters. Hand-placement and repeaters are obviated though the use of ad hoc routing, localization, array processing, and data aggregation.