Sensors (IMAGE) University of Southern California Caption The USC Smart Fence system uses combined input from three sensors (top to bottom: motion, acoustic, and seismic), looking for spatiotemporal patterns of perimeter intrusion. Credit USC Viterbi School of Engineering Usage Restrictions credit Viterbi School of Engineering License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.