July/August 2019 I 23
Detect
Early detection of an attempted incursion anywhere
along the perimeter is the objective of this application,
which involves the deployment of an appropriate
technology that can accurately detect unauthorized
incursions and encompass large areas of space outside
the perimeter boundary or immediately along the
length of the perimeter.
Some of the many detection technologies available
include GPS tracking technology that provides real-time
geo-spatial data for viewing perimeter activity, perimeter
intrusion detection sensors, and ground-based radar. The
selected technology needs to provide an appropriate level
of notification of any attempted incursion in a very
timely manner to support the immediate response
by authorized personnel. Considerations for possible
incursion routes, such as over, under or through, must
be the primary paradigm in applying the appropriate
detection to meet this element of security-in-depth.
Additionally, the technology must also provide
a level of performance that ensures a high probability
of detection with a certain degree of immunity against
invalid or nuisance alarm alerts. Nuisance alarms can be
caused by outside sources, such as acoustical and environmental
conditions, as well as non-human interaction
(e.g., animals, birds, rodents). This technical concern
stands above all others in the 5D strategy as the most
critical and difficult to accomplish.
When selecting protective measures, it is important
that the equipment conforms to the needs of the threat,
performs consistently in all environmental conditions,
FIGURE 3: Managing or directing normal vehicle and
pedestrian traffic to strategically controlled entry
points to deny unauthorized access can be enhanced
by supplementing with K-rated gates and barricades
and the addition of HD video surveillance cameras.
The greatest challenge in designing
and implementing perimeter
security measures based on the
security-in-depth strategy lies
in the very nature of the assets being
protected and the potential threats
facing those assets.
and adapts easily to support future expansion
as conditions, risks, and threats change.
Deny
The objective of this element is to deny—at the
immediate perimeter boundary—entry to any
unauthorized persons while allowing authorized
persons to enter.
The deny element typically involves configuration
of the perimeter boundary to manage or direct normal
vehicle and pedestrian traffic to strategically controlled
entry points (Figure 3).
As part of the overall 5D strategy, proper application
of the deny element should also incorporate all elements
of deter and detect in order to enhance the remaining
non-traffic channeling areas of the perimeter
against incursion.
The use of physical access control system technology
and the posting of manned security gates at the points
of entry are considered among the best methods
to channel vehicle and pedestrian traffic.
These measures should be supplemented with
protective lighting enhancements at an IL luminance
of 21.52 lux (2.0 footcandles) or better, installation
of K-rated gates, bollards or barricades, and the addition
of HD video surveillance cameras; by doing so, the
deny element of 5D strategy now forms part of the
overall security program.