Detection of Suicide Bomber Threat Using a Dual Radar System

Detection of threat targets, which consist of different types of shrapnel, has been evaluated for a dual radar system designed and manufactured by Safe Zone Systems, New Mexico. The Safe Zone product consists of two spread-spectrum, interrupted continuous-wave (CW) radars operating around 10 GHz. The radars are able to detect anomalies on the human body that would be associated with suicide bombers. Suicide bombers generally hide a small explosive device on their body, along with several pounds of shrapnel; it is generally accepted that the shrapnel is what causes the majority of the deaths and injuries to bystanders. The Safe Zone device was tested by Sandia National Laboratories using the following targets: nails, random nuts and bolts, glass marbles, broken glass shards, ball bearings, ceramic shards, and rocks. The test results indicated that the Safe Zone system correctly identified, approximately 95% of the time, when a subject was carrying targets on Side A and/or Side B of their body. The purpose of this paper is to present the results of the “Design of Experiments” (DoE) tests used to assess the detection quality of this radar system and to provide details on the detection capability of the radar system. Designed experiments were used to • minimize the number of tests required to characterize the Safe Zone system; • provide a more structured approach to data gathering; and • maximize the data generated Human subjects varying in height and weight donned a vest that accommodated the insertion of a shrapnel-threat target. For the 10+ distinct trials run for each subject in these tests, a randomly-generated table designated whether a target was inserted into the vest or not, what that target was, and at what level of the body it was placed. Detection was monitored at both Side A and Side B of the subject, often with differing shrapnel targets. Although the detection of false negatives, i.e. missed targets, was higher on one side than on the other side, the combined detection was relatively high. This system has potential impact for the protection of government buildings, embassies, or any type of public location where attendees can be screened before enterin