Conventional night vision systems improve the
user’s ability to "see" objects by enhancing
visible light. These systems only work if there
is at least a minimal amount of available light
and if there is nothing obscuring visibility
(such as dust, haze, fog, or smoke). FLIR
cameras are still highly effective under
conditions of low-visibility or complete
darkness. By providing an image of the infrared
energy being emitted by objects, the system can
still "see" in complete darkness or obscured
visibility. While the effectiveness of the
system may be diminished when viewing distant
objects under obscured conditions, FLIR infrared
cameras still provide better visibility than
other night vision enhancement systems. Because
it measures thermal energy, FLIR infrared
cameras can be used to conduct surveillance
without relying on search lights or special
lighting, improving the user’s ability to remain
undetected.
The military advantages of these early systems
were significant. Naval vessels could still
detect and target enemy ships, even on the
darkest nights or under foggy conditions. As one
might imagine, these early systems were large,
heavy, and expensive. During the past decades,
however, FLIR cameras have been adapted for use
aboard all types of aircraft, naval vessels, and
ground vehicles; in recent years some
manufacturers have even developed handheld
units. Technological advances have significantly
lowered the size, weight, and cost of FLIR
sights. These new systems may offer reliable
service without requiring extensive or costly
upkeep.
Handheld FLIR scopes weight less than five
pounds and may be within the price range of many
law enforcement agencies.
LAW ENFORCEMENT APPLICATIONS
FLIR systems have been successfully used by a
number of major law enforcement agencies in
recent years. Until recently, FLIR cameras has
generally been a tool for aviation units.
Mounted on a helicopter, a FLIR camera could
assist in pursuits and Search and Rescue
missions. The systems were still expensive and
somewhat cumbersome. Because aviation units were
most likely to respond to situations where FLIR
imagers could be of use, this was a logical use
of this resource.
More recently, law enforcement agencies have
begun experimenting with FLIR infrared cameras
mounted on ground vehicles or as independent,
handheld units. Lubbock, Texas, has FLIR
infrared imaging cameras integrated into their
canine vehicles. A canine vehicle is likely to
become involved in search or pursuit operations,
so deploying ground vehicle systems with these
units makes sense. As technologies improve and
costs continue to decrease, it may be more
common to see ground vehicle mounted or handheld
FLIR infrared cameras being used to support a
wide variety of law enforcement applications. As
a tool to assist in either pursuits or Search
and Rescue missions, FLIR cameras offers several
advantages to police organizations. While it was
designed for use during operations taking place
at night or under obscured visibility
conditions, FLIR imagers can also be used during
day light hours. For example, a search for a
missing child or a fleeing suspect might lead to
a farm field. Depending on the nature and
density of the foliage, an aviation unit
equipped with FLIR IR cameras might be able to
locate a child or suspect who might otherwise be
hidden from plain view, even during daylight
hours.
Many FLIR thermal infrared imaging cameras are
designed to videotape what the operator sees. In
addition, units may also serve as daylight video
recording systems. These features allow officers
to generate evidence which might be very helpful
in prosecution. For example, a helicopter
equipped with FLIR sensor could assist ground
vehicles in a high-speed pursuit of a stolen
automobile. As soon as the helicopter arrived in
the area of the pursuit, it could begin to
record the events occurring on the ground. The
system could videotape the infrared image of the
driver "bailing" from the vehicle and fleeing
into a residential neighborhood. The system
could continue to videotape the suspect as he
fled through backyards and assist aviation
personnel in directing officers on the ground in
order to make an apprehension.
Having the chase on tape would provide
incontrovertible proof that the suspect taken
into custody was indeed the driver of the stolen
vehicle (and not an innocent citizen "looking
for a runaway cat"). Because the system is not
dependent on the use of a search light (which
might produce shadows and distortions on a
videotape), it might also show that officers
used appropriate force in taking a suspect into
custody, thus limiting potential liability.
FLIR thermal infrared imaging cameras may be one
of the best options for vision enhancement under
conditions of obscured visibility. Some
jurisdictions frequently encounter problems due
to fog or haze. Vision systems which amplify
available light may be less effective under such
conditions. While FLIR does have a limited
ability to penetrate smoke, dust, haze, or fog,
it is generally more effective than the naked
eye or conventional night vision enhancement
systems under such conditions. Police marine
units may be find it easier to engage in routine
patrol or search and rescue operations with a
FLIR imaging camera, even under conditions of
heavy fog (and even during daylight hours). Fire
departments have been using helmet-mounted FLIR
infrared camera for several years to aid
personnel in searching for victims in fires.
Although FLIR cameras cannot penetrate all of
the smoke generated by a burning building, it
can improve a fire fighter’s ability to "see."
These systems not only allow fire fighters to
conduct a more thorough search in less time, but
a search could be done with fewer personnel,
placing fewer lives at risk in the performance
of dangerous operations. FLIR thermal infrared
imaging cameras can also be a valuable tool for
police personnel conducting surveillance or
security operations.
Because the system works without relying on
light sources, it can be operated in a covert
manner. Personnel surveilling a dark parking lot
could observe potential victims or suspects
without alerting these party’s to their
presence. Individuals can be clearly seen, even
under conditions of complete darkness. These
applications might enhance to covert nature of
surveillance operations and decrease the number
of personnel required to conduct such an
operation.
FLIR sights, scopes, and cameras may also be
used to take a thermal image of a person,
luggage, buildings, automobiles, trucks, or
boats (generally in an effort to search for
drugs). While FLIR infrared cameras can not see
through walls or doors, they can detect
temperature differences which might indicate the
presence of hidden compartments or contraband. A
thermal scan may indicate if a person has
something secreted beneath their clothing, or if
the hold of a ship contains ice-cold fish or
something with an even greater street value.
Growing marijuana indoors requires the use of
high-temperature artificial lighting; a thermal
scan of a neighborhood might indicate if a
specific house has an unusual hot spot which
might indicate that such indoor gardening is
taking place.
It must be noted that the courts have not fully
resolved how police officers can use thermal
images in carrying out drug or contraband
detection. Some federal circuit courts have
viewed thermal imaging as equivalent to any
other search.
As such, police officers in these circuits may
need either explicit probably cause or a search
warrant in order to use thermal imaging. Other
circuits have taken a more liberal stance,
allowing law enforcement personnel to engage in
random thermal imaging. Readers would be well
advised to check the status of FLIR imaging as a
search within their state and federal district
courts before undertaking such operations.
INCREASED EFFICIENCY WITH FLIR
FLIR infrared camera offers a clear way for law
enforcement agencies to operate in a more
efficient and effective manner. As a tool for an
aviation unit, FLIR thermal infrared imagers can
significantly reduce the time needed to conduct
a search. Agencies using FLIR cameras might also
have an easier time tracking and apprehending
fleeing suspects. FLIR infrared cameras make
pursuit and search operations more efficient and
also safer.
Suspects or victims can be quickly located.
Officers on the ground can be directed to these
locations without conducting prolonged, and
potentially dangerous, searches.
As a surveillance tool, FLIR thermal infrared
imaging cameras may allow agencies to carry out
some operations with fewer personnel and in a
more covert manner. Officers can surveil areas,
even under complete darkness. Under some
conditions, FLIR infrared cameras may also
allows users to detect well camouflaged
individuals. Because many FLIR imagers allow for
the generation of video recordings, it is easy
to produce evidence suitable for use in the
courtroom. Such evidence may enhance the
likelihood of prosecuting defendants in cases
where the cover of night might have otherwise
made suspect identification difficult.
The
use of FLIR technology can allow for agencies to
conduct certain operations with fewer personnel.
In addition, those personnel involved in such
missions might be able to perform their duties
with an enhanced degree of safety and security.
The current cost FLIR systems may preclude some
law enforcement agencies from enjoying these
benefits. Despite the current cost of FLIR
systems, it is likely that purchasing and
maintenance costs will continue to decline,
while performance improves in the years to come.