NOTE:
Laser weapon simulators are used in machine guns, tanks, cannons, and
artillery as well as air-to-air gunnery systems to train military personnel.
The laser system is pulse-coded to identify the hit soldier, weapon, tank,
etc.
d. Security Surveillance Systems. A laser-beam-aided security surveillance
system can be used to detect unlawful happenings at strategic military grounds. The
system can sound an alarm or produce a display on an instrument panel to alert the
authorities of an intruder. Such a system can be used in and around military
installations. The system can also be used for private purposes to protect civilian
property against vandals, thieves, arsonists, and other criminals. Such systems have
been put into service in the past with ordinary white light as detectors. A bird, cat, or
dog could trip the system by crossing the path of the beam. The central station was
notified, but the notification was an accident. Now, with the advent of laser beams, the
light beam is invisible and of high intensity and can be directed to indicate exactly where
something happened.
e. Range Finders. Range finders are instruments used to measure distances.
Laser range finders and radar range finders work much the same way. Each sends out
a signal to an object. By knowing the time it took for the signal to get to the object and
bounce back to the sender, the distance from the sender to the object can be
determined. The weakness of using radio waves is that they are bigger than light
waves and become weaker as they travel (they run into interference). Laser range
finders, traveling greater distances, can be used to keep track of rockets and satellites.
Accurate measurements in land surveys and construction work can be made with laser
range finders. Scientists in a laboratory can measure the space between two atoms by
using a laser range finder.
f. Communications. Like radio waves, laser beams can be used to send
communications signals (telephone, television, and radio). Astronauts in space have
communicated to earth by laser beam. Laser communications go through space better
than through the earth's atmosphere. The reason is that in space there are no clouds,
rain, snow, or smog to weaken the laser beam's power.
Figure 2-15. Measuring distances by laser beam.
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