Most people are familiar with the concept
of night vision. After all, it is seen
in countless action and spy movies. However,
the truth is that night vision is more
than a fantastical concept; it is reality.
And with goggles, night scopes, binoculars
and monoculars, it is possible to see
on a moonless, cloudless night. In fact,
the technology is so advanced that you
can see a person standing more than 200
yards away. That's twice the length of
a football field! The remarkable feat
of human sight at night is accomplished
one of two ways: image enhancement or
thermal imaging.
Image enhancement is a night vision technique
that collects tiny amounts of light that
may not be perceptible to the human eye.
These are the smallest glimmers of light,
sometimes even on the lower end of the
infrared spectrum, that are discovered
by the device in use. The points of light
are than amplified by the device to a
point that allows the object or person
to be seen easily.
The other way night vision works is by
thermal imaging. This is technology that
works exclusively in the upper portion
of infrared light. Rather than gathering
reflected light, this is heat that is
given off by objects or people. This is
known as thermal infrared, and it occupies
the largest amount of space as part of
the infrared spectrum (which is at the
lower end of the light spectrum, below
what is detectible by the human eye).
This means that there is a great deal
of wavelengths that can be detected by
the proper devices. Because thermal imaging
works by putting the heat coming from
objects in visible form, it is to be expected
that some objects will appear clearer
than others. Humans, for example, emit
more heat than a tree, and so a tree will
not be as clear.
Night vision products make excellent
additions to any surveillance collection,
and they can be very helpful in locating
objects or people in dark places. You
will pay in a price range from under $300
to more than $15,000, depending on features,
accuracy, and purpose of the accessories
you choose to aid your night vision.
(c) 2005 Copyright www.spyassociates.com.
This article is about: Night Vision
This article was posted on September
30, 2005
