U.S. flag

An official website of the United States government, Department of Justice.

Through-the-Wall Sensors Advance Tactical Awareness

NCJ Number
Techbeat Dated: July/August 2014 Pages: 7-10
Date Published
July 2014
4 pages
This article reviews advances in through-the-wall sensor (TTWS) technology, which has improved law enforcement's capability to detect the presence of individuals inside a building from a distance.
TTWS uses radar to detect even slight motions through building walls, thus providing law enforcement officers with increased knowledge of a suspect's or victim's location in a building prior to entering it. The Sensor, Surveillance, and Biometric Technologies Center of Excellence (SSBT) recently concluded the second and third segments of a three-part research project on TTWS, which was sponsored by the National Institute of Justice (NIJ). Four recommendations emerged from the project. First, practice with the device, because it is important to understand the technical nuances in order to build confidence in the information obtained from the TTWS and incorporate it into tactics. Second, view TTWS as a tool, but not as a substitute for tactical training. TTWS assists in providing information about a situation, but should not dictate a course of action. Third, take multiple measurements at different places along a given wall, since the composition of a wall is not uniform; studs, water pipes, and other structural variances can produce skewed results. Fourth, since solid metal can block radar signatures, structures such as rebar or chicken wire can interfere with results.

Date Published: July 1, 2014