This paper appeared in the Proceedings of the Military Sensing Society (MSS) National Symposium, Las Vegas,
Nevada, U.S., July 2010.We report on experiments with a nonimaging sensor network for detection of suspicious behavior related to
pedestrian emplacement of IEDs. Emplacement is the time when detection is the most feasible for IEDs since it
almost necessarily must involve some unusual behaviors. Sensors at particularly dangerous locations such as
bridges, culverts, road narrowings, and road intersections could provide early warning of such activity. Imaging for
surveillance has weaknesses in its susceptibility to occlusion, problems operating at night, sensitivity to angle of
view, high processing requirements, and need to invade privacy. Our approach is to use a variety of nonimaging
sensors with different modalities to track people. We particularly look for clues as to accelerations since these are
often associated with suspicious behavior. Our approach involves preanalyzing terrain for the probability of
emplacement of an IED, then combining this with real-time assessment of suspicious behavior obtained from
probabilities of location derived from sensor data. We describe some experiments with a prototype sensor network
and the promising results obtained.supported by the U.S. National Science Foundation under grant 0729696 of the EXP ProgramApproved for public release; distribution is unlimited
