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. Deterrence
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 surveillance
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 boundary
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.
22 I ICT TODAY
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 installations,
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 illumination.
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.