DCSIMG
Skip to local navigation | Skip to content
Office of Justice Programs (OJP) banner
National Institute of Justice (NIJ): Research, Development, Evaluation
 

Through-the-Wall Surveillance

Call to Manufacturers

NIJ is seeking manufacturers interested in supplying through-wall sensor devices for a planned evaluation. The evaluation will focus on field operation in civilian law enforcement scenarios.

Find details in the Federal Register.

Through-the-wall surveillance (TWS) technology detects motion through interior or exterior building walls. It can penetrate brick, reinforced concrete, concrete block, sheetrock, wood, plaster, fiberglass and common building materials, but not solid metal (e.g., it can "look" through rebar reinforced concrete but not a solid metal wall).  It can be used, for example, to locate and track individuals inside a building during hostage rescue operations.

Some TWS devices must be placed next to the structure; others can operate at a distance from it, enabling building searches from a vehicle or other safe cover.

Refinements in technology and policy have overcome many barriers posed by earlier versions, which were often costly, had to be placed near or directly up against the wall, or were approved for use by the military but not law enforcement.

Standoff Through-the-Wall Device Approved for Law Enforcement Use


3Akela Standoff Through-the-Wall Imaging Radar
View a larger version that demonstrates how the system works

NIJ supported the development of the first standoff through-the-wall surveillance device approved for law enforcement use. 1 The Akela Standoff Through-the-Wall Imaging Radar; a portable radar system that can, from a distance, map and image the internal structure of a building and locate living personnel inside the structure. It can detect a motion as small as the that of a person breathing. The system can be networked, runs remotely using wired or wireless Ethernet, and provides the controls and display through a regular laptop computer. NIJ is funding further development and testing and evaluation in operational settings.

Read the 2007 NIJ Journal article "Through-the-Wall Surveillance: A New Technology for Saving Lives."

Notes

[1] In late 2011, Akela received a waiver from the Federal Communications Commission to produce a system the use of which is "limited to state and local police and firefighters, and … limited to actual emergencies involving threats to safety of life, and necessary training." View the complete text of the waiver on FCC.gov.

Date Modified: October 1, 2012