Year
1999
Abstract
Outdoor perimeter volumetric field disturbance sensors reliably detect peturbations to the field caused by an intruder, while rejecting noise and environmental changes that may be orders of magnitude greater than the target response. Currently, E-Field systems are widely deployed in nuclear, Correlational and undustrial sites to provide perimeter security. These systems are effective in rejecting the majority if noise and environmental stimuli through combined fixed attribute threshold comparison techniques. However, some environmental stinuli closely mimic target stimuli, so improved discrimination techniques have been sought. This paper describes the reults of vurrent studies and investigations of electrostatic sensor system response to targets and to various environmental changes. Fundemental principles in the character of sensor response to these varied stimuli are discussed. Techniques and methods that may be used to exploit the difference between intruder and environmental responses, while using cost-effective discrimination methods, are described. It is shown how a new system can be created, using currently available technologies, to provide both excellent detection properties, and an extremely low nuisance alarm rate, while at the same time greatly simplyfying installation, calibration and maintenance.