Issue link: https://www.e-digitaleditions.com/i/1132978
22 I ICT TODAY OVERVIEW OF THE 5 Ds Deter The deterrence element in perimeter protection provides a level of security awareness at the outermost property line or boundary with respect to the protected asset or target. The objective is to deter the perpetrator from even attempting to breach the secure perimeter. Deter- rence is a psychological element, and it depends heavily on perception. This application often relies on a mix of physical barriers that fall under two category types: natural and structural. Additional psychological perceptions include wide, open and clear lines of sight; enhanced lighting conditions; deployment of overt video surveil- lance system technologies; posting of warning signage; and the use of highly visible and obvious security patrols. Natural barriers include mountains, cliffs, canyons, rivers, or other obstacles that are difficult to traverse. Structural barriers are man-made devices, such as fences, walls, grilles, bars, buildings or other structures, which can establish a perimeter boundary that deters penetration or incursion at the perimeter. The presence of a natural barrier or structure forming part of the perimeter bound- ary should not, however, automatically be considered an adequate perimeter deterrent, because these obstacles may easily be overcome by a determined intruder. The natural barrier should be carefully evaluated from a security perspective, and additional protective measures FIGURE 2: Protective lighting and security warning signage are valuable crime prevention tools. may be warranted so that these portions of the perimeter boundary afford a greater degree of deterrence to unwanted incursions. Protective lighting is another valuable crime prevention tool, improving visibility through the reduction of blind spots or shadowed areas that could possibly offer concealment for intruders as shown in Figure 2. For facilities, such as airports and military installa- tions, the Unified Facilities Criteria (UFC) standard (UFC 3-530-01) for the Department of Defense (DOD) recognizes as a standard a minimum IL luminance of 5 lux (0.5 foot candles) for a "horizontal target" when deploying perimeter fence-line protection. Protective lighting should always be designed with the following considerations: • Locate perimeter lighting to support a balanced illumination of both sides of the perimeter fence- line at a minimum IL luminance of 5 lux (0.5 foot candles). Locate the lighting fixture on the inside or perimeter to prevent tampering. • Design lighting to permit overlapping illumina- tion. Do not leave dark spaces or shadow areas between lighted areas in which perpetrators can move undetected. • Install lighting fixtures facing down and away from target or asset to create glare for an approaching intruder. • Ensure the lighting does not hinder observation by security patrols. • Provide a lighting design to ensure maximum performance of any surveillance cameras deployed and ensure cameras are not negatively impacted by the lighting systems. Posting signage around the perimeter of the site that stipulates "no trespassing, violators will be prosecuted" or "area under video surveillance" aids greatly in communicating the deterrence message to unauthorized persons. Applying surveillance technology in an overt manner through the deployment of highly visible video surveil- lance cameras, making it obvious to anyone approaching the perimeter that they are under constant surveillance, is another sound method of deterrence.