Night Vision Systems
Night
vision technology allows you to clearly distinguish objects at night,
even at distances of up to several hundred yards, in the absence of
artificial light. You can see boats, people, buoys, jetties, shorelines,
channel markers, and anything else that you would only see as indistinct
shadows with the naked eye. It's important to understand that night
vision systems amplify existing light and will not operate in the absence
of all light, i.e. a cave, sealed basement, etc. Some models have infrared
which sends out a beam of light that is multiplied. This allows for
viewing in complete darkness and is particularly good for locating buoys
with reflectors attached to them.
A Brief Overview
Night vision systems provide electronically enhanced viewing. When you
use a night vision system, you are not actually viewing the scene before
you, but rather a video image of that scene through a video camera with
an extremely high sensitivity to light. The system picks up the available
light reflected from the objects being viewed, and converts the radiant
energy of the light to electrical energy in the system. The electrical
charge then becomes an accurate representation of the scene being viewed.
Performance Specifications
Night vision systems vary widely in performance, so it's important to
recognize some basic performance criteria. The three most commonly cited
specifications:
- Light Amplification
refers to the amount of light multiplied.
- Sensitivity is the
light threshold at which the system will operate, the relative darkness
if you will, under which it will perform.
- Resolution is an indication
of the amount of detail you will be able to distinguish through
the system.
Although this is a simplified
explanation of night vision systems, it helps give a working knowledge
of how these systems work. If you do any night time boating, do yourself
a favor-don't be left in the dark!
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