Open Area Concealed Weapon Detection (CWD) Sensor System and Algorithm Development

A concealed weapon detection (CWD) system is proposed, to accurately differentiate between threatening and non-threatening objects, based on electromagnetic pulse-induction (PI). The resultant induced magnetic field generated from an object, is detected via a sensing coil and converted, in real-time, to a single bit data stream via a sigma-delta (\Sigma\triangle) modulator, forming a digital signature. A comparison of a no-object background signature with that of a detected object, enables specific characteristics of objects, specifically concealed weapons to be identified. The benefit of this system is the potential for accurate identification of different target objects by the analysis of the received response. This will ultimately enable the requirement for only the manual screening of individuals that are carrying threat objects. A novel algorithm is presented, to measure the time points of the object signature, which identify the featured object decay signal, so that the comparison of time points can achieve the distinction and classification of the detected targets enabling threat objects to be distinguished from non-threat objects.