The development of a methodology for the evaluation of Wide Area Detection Systems (WADS)

Abstract

The UK Home Office Centre for Applied Science & Technology (CAST)1, in partnership with the Centre for the Protection of National Infrastructure (CPNI), has been developing a suite of standards for the testing of Perimeter Intruder Detection Systems (PIDS). This paper describes the development of the fifth standard in the suite, which is a methodology for the evaluation of a category of PIDS known as Wide Area Detection Systems (WADS). WADS are radically different to the PIDS covered by standards to date. Conventional PIDS have an essentially linear detection zone; whereas WADS provide surveillance over an extensive area, rather than along a line. Their range tends to be substantially greater than that of other PIDS; and system functionality is more sophisticated. In practice a WADS may be deployed to protect a large area, including a range of topographical features and obstacles (such as buildings). This complicates meaningful evaluation of products on a comparative basis, and makes setting performance criteria non-trivial compared to conventional PIDS. To address this, it is proposed that performance evaluations are carried out over as clear and benign an area as possible. Within this clear area evaluation, additional performance criteria not usually associated with linear PIDS will be assessed, such as maximum / minimum detection range, detection consistency, plot accuracy and the ability to “mask-out” areas within the detection envelope. In addition, to take account of real-world operational factors, such as undulating terrain, vegetation and man-made obstacles; time-to-alarm; and camera cueing, systems will also be assessed over a cluttered test area. However, relative performance in such an environment will be assessed on an indicative basis only, as it is not practicable to apply pure performance indicators in this case. In summary, it is proposed that rigorous quantitative assessment of performance will be carried out over a clear area of ground. This will be supplemented by indicative comparison of performance over a cluttered test area to demonstrate system behaviour in a more realistic setting, and to enable more sophisticated aspects of functionality to be assessed. This dual-faceted evaluation will support a guidance-led approach to the selection and use of WADS by UK Government and Critical National Infrastructure end users.