2. • Radar is an object detection system which
uses radio waves to determine the range,
altitude, direction, or speed of objects. It
can be used to detect aircraft, ships,
spacecraft, guided missiles, motor vehicles,
weather formations, and terrain. The radar
dish or antenna transmits pulses of radio
waves or microwaves which bounce off any
object in their path. The object returns a
tiny part of the wave's energy to a dish or
antenna which is usually located at the same
site as the transmitter.
3. History of radar
• Radar was secretly developed by several
nations before and during World War II.
The term RADAR was coined in 1940 by
the United States Navy as an acronym
for RAdio Detection And Ranging. The
term radar has since entered English and
other languages as the common
noun radar, losing all capitalization.
4. APPLICATIONS
• The modern uses of radar are highly diverse,
including air traffic control, radar astronomy,
air-defense systems, antimissile systems
; marine radars to locate landmarks and other
ships; aircraft anticollision systems; ocean
surveillance systems, outer space surveillance.
High tech radar systems are associated
with digital signal processing and are capable of
extracting useful information from very high
noise levels.
5. • The information provided by
radar includes the bearing
and range (and therefore
position) of the object from
the radar scanner. It is thus
used in many different fields
where the need for such
positioning is crucial. The
first use of radar was for
military purposes: to locate
air, ground and sea targets.
This evolved in the civilian
field into applications for
aircraft, ships, and roads.
Commercial marine radar antenna. The rotating antenna radiates a vertical fan-shaped beam
6. • Israeli military radar is typical of the type of
radar used for air traffic control. The
antenna rotates at a steady rate, sweeping
the local airspace with a narrow vertical
fan-shaped beam, to detect aircraft at all
altitudes.
7. • A long-range
radar antenna, known
as ALTAIR, used to
detect and track
space objects