Ultrasonic through-the-wall surveillance system

A handheld through-the-wall surveillance system is being developed for use by law enforcement and military personnel. The system utilizes high-power ultrasonic transducers to detect and locate stationary or moving persons inside metallic and nonmetallic walled enclosures. Design details are presented with proof-of-concept data and analyses. The sensor system is being designed to operate as a handheld monitor with a near real-time user display of the location, in range and azimuth, of each detected individual. Preliminary test data include wall penetration/sensitivity, locating accuracy, and probability of detection. Applications of this technology include detecting and locating unconscious, sleeping, tightly bound, or otherwise stationary persons, as well as moving persons, inside a closed room. The sensor should also prove useful in border patrol applications for inspecting truck trailers and shipping containers at points of entry.