Brief
History
The
history
of radar dates back to World War I, when a number of
scientists contributed to its invention. The most prominent among
them was a Scottish physicist named Robert Watson-Watt, who was
appointed by Britain's Meteorological Office to facilitate the use
of radio waves to detect approaching storms during World War I.
However, it was only during World War II that Watson-Watt, along
with his assistant, thought of using the technology for detecting
approaching enemy aircrafts or other such obstructions.
Working
The
working of radar system
on an airplane begins from the time it’s installed onboard. The
radio waves emitted from the radar are very similar to those of
light and are transmitted by equipment in its system known as
magnetron. A magnetron transmits microwaves composed of wavering
patterns of electrical and magnetic energy, traveling at a speed
almost equivalent to light waves but with longer wavelengths and
higher frequencies. Generated waves are forced in to the air by an
antenna that works as a transmitter. These curved radar antennas
focus the waves into precise, narrow beams and even rotate to
detect movements over an expansive area. The waves travel from the
antenna at light speed and travel continuously till they hit an
obstruction, and some of them are bounced back to the antenna. The
traveling speed of these waves needs to be high, as signals need
to travel faster than the obstruction. As radio waves travel at
light speed, they are faster than most of the objects.
The
antenna is both the transmitter and receiver of the radar. First
it transmits the waves and then it waits for the reflected waves,
which are then directed to electronic equipment where they are
processed and displayed in a consequential manner on a
television-like screen overlooked by a human operator. Moreover,
the radar equipment is so designed that it displays only relevant
reflections, filtering those from other sources such as ground,
buildings etc. The radar enables the operator to view nearby ships
and planes, their location as well as speed and direction. An
airplane radar is an extremely important device during foggy
conditions, as bad weather cannot obstruct radio waves and thus is
highly beneficial in helping an airplane easily navigate.
Recent
Advances
The
radar technology has come a long way since the time of its
invention. However, the most noteworthy advancement in radar
technology has been the phased-array radar wherein hundreds of
tiny antennas are geometrically positioned to correlate the
transmitted and received signals in terms of phase. Moreover,
stealth technology has also been developed so that enemy radar
cannot spot the aircraft carrying missiles and bombers. The
stealth technology is designed on a special technology that allows
it to scatter or absorb beams of radio waves. There are also spy
airplanes which are so efficient that while they show on the enemy
radar, it appears to be similar to the size of a swift bird,
allowing it to pass speedily and undetected.
References
"Radar"
Science World: http://scienceworld.wolfram.com/physics/Radar.html
"How
Radar Works" Explain That Stuff: http://www.explainthatstuff.com/radar.html
[Source:
Bright
Hub]