During Phase I, it is proposed that RADAR Flashlight, LLC (RFLLC), will demonstrate that a hand-held TWS sensor, requiring no stabilization, can be developed. It will be demonstrated that a hand-held TWS sensor capable of detecting the respiration signature of a human subject behind a wall is feasible. The feasibility of a self-stabilized sensor will be demonstrated through two experiments utilizing hardware and software to be developed. Each experiment will demonstrate a different stabilization design approach. Each approach will be evaluated. The hand-held stabilization technique showing the most promise will be proposed for transition into a DARPA Phase II development program for final pre-production model prototyping and commercialization. More specifically, it will be demonstrated during the proposed DARPA Phase I TWS research program that: 1) Stabilized hand-held operation requiring no placement of the TWS against the wall or on a tripod for stabilization can be achieved using two techniques; 2) The respiration signature of a human can be detected while the human is behind an opaque barrier such as a wall or door and the TWS is being hand held; 3) A display technique that will allow the user to determine the details of the interior of the structure being probed for human presence can be achieved; 4) The proof of principles demonstrated in the Phase I effort may be applied to a longer range stand-off system with possible weapons detection capability; 5) A TWS featuring all weather, robust, man portable (small and lightweight), system, operable by one soldier can be designed and produced and; 6) That the TWS can be commercialized at a price not to exceed $ 5,000 per unit, to allow large quantity purchases by both the military and homeland defense agencies