Investigation of Methods for Improving Intruder Detection Efficiency in Physical Protection Systems

Abstract

The article presents a comprehensive investigation of methods for increasing the intruder detection efficiency in physical protection systems (PPS) of facilities. In the context of increasing technical training of potential attackers, in particular their ability to use passive and active means of overcoming PPS, there is a need for a formalized approach to assessing the effectiveness of detection devices (DT). The paper analyzes the factors that influence the probability of detecting unauthorized intrusion (UI), among which the determining factors are the direction and speed of the intruder's movement, the effective reflection/emission area, environmental parameters, and the technical characteristics of the detector. A system of criteria has been developed for a comprehensive assessment of DT effectiveness: the criterion of ensuring the required probability of detection in any direction of movement, the criterion of minimizing the probability of false alarms, the criterion of incompatibility of the effective actions of the intruder with respect to several detection channels, as well as the criterion of minimizing the maximum detection distance. Particular attention is paid to the structuring of the directional diagram (DD), which allows to distinguish zones of confident detection, partial detection and non-detection zones. The relationship between the spatial sensitivity of the detector and the parameters of the intruder's movement has been formalized. The methodology of modeling trajectories of possible attacker movement was applied to assess the effectiveness of the response of different types of DT. The advantages and limitations of passive infrared (PIR), radio wave (RW), and combined detectors are analyzed in the context of compliance with the formulated criteria. Approaches to combining different types of DT are proposed to achieve maximum sensitivity and minimum vulnerability of the system as a whole. Based on calculated and experimental data, the effectiveness of using spaced orthogonal combined detectors, which allow ensuring resistance to the actions of the violator in conditions of multi-variant movement, is substantiated. It has been shown that this structure provides the best balance between detection probability and false alarm frequency. The proposed methodology can be used as a tool for optimizing PPS at the design, modernization, or testing the effectiveness of existing solutions in the field of physical security.