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Abstract / Summary……………………………………………………………….….01
History Of Radars….……….……………………...………………………..……03-07
• Early Experiments.
• First Military Radars.
• Advances during World War II.
• Post War Progress.
• Radar in Digital Age.
Principles of Radar………………………………………………………………..08-10
• Basic Principle.
• Technical Principle.
• Radar Equation.
Applications Of Radars………………………………..………………………….11-14
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The subject matter of electrical engineering may be classified according to (1) Components
(2) Techniques, and (3) Systems. Components are the basic building blocks that are
combined, using the proper techniques, to yield a system. This project attempts to present a
unified approach to the systems aspect of radar.
This project is divided into four parts. The first part deals with characteristic of radar per se
and includes a brief introduction and historical survey.
The second part is concerned with the subsystems and the major components constituting a
The third part treats various topics of special importance to the radar system engineer. These
include the detection of signals in noise and the extraction of information from radar signals,
both of which are based on modern communication theory and random-noise theory.
The last portion of the book deals with radar systems and their application.
To attempt to treat thoroughly all aspects of a radar system, its component parts, and its
analysis is an almost impossible task within a small project, since the subject of radar
encompasses almost all electrical engineering. Extensive references to the project are
included for those most desiring.
Radar has been used on the ground, on the sea, and in the air, and undoubtedly it will be used
in space. The environment in which a specific radar operates will have an important influence
on its design.
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RADAR means "Radio Detection and Ranging." Radar is a system that uses
electromagnetic waves to determine the presence, direction, distance, speed and
size of objects like aircrafts, ships, spacecraft, weather formations, and terrain.
The term RADAR was coined in the 1940s, though the first "practical" use of radio waves for
RADAR was invented by Christian Huelsmeyer in 1904. Radar usage surged during World
War II as both the German and English military used it for naval and air defence. Since
World War II radar has become an essential part of everyday life, providing weather
information and air traffic data.
Radar arrays generate radio waves that bounce off possible targets like ships, planes,
satellites or even planets, and echo back to the radar system. Computers decode the
information in the echoes to determine the size, shape, distance, speed, trajectory and
composition of radar targets.
Since 1940 radar has found a number of uses in: airport surveillance, weather surveillance,
satellite radar and traffic enforcement.
Radar arrays can range in size from hand-held units used by traffic enforcement officers to
building-sized arrays used to study hurricanes.
Radar can use high-energy radio waves to gather data. Such radio waves can be harmful to
biological tissue. Exposure to high-level electromagnetism has been shown to cause
mutations in DNA.
Radar was the product of at least two centuries of investigation into the laws of
electromagnetism, and was not simply invented by the British during World War II.
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Serious developmental work on radar began in the 1930s, but the basic idea of radar had its
origins in the classical experiments on electromagnetic radiation conducted by German
physicist Heinrich Hertz during the late 1880s. Hertz set out to verify experimentally the
earlier theoretical work of Scottish physicist James Clerk Maxwell. Maxwell had formulated
the general equations of the electromagnetic field, determining that both light and radio
waves are examples of electromagnetic waves governed by the same fundamental laws but
having widely different frequencies. Maxwell’s work led to the conclusion that radio waves
can be reflected by metallic objects. However, it was not until the early 20th century that
systems were able to use these principles were becoming widely available, and it was
German inventor Christian Hülsmeyer who first used them to build a simple ship detection
device intended to help avoid collisions in fog. Numerous similar systems were developed
over the next two decades.
The term RADAR was coined in 1940 by the United States Navy as an acronym for radio
detection and ranging; this was a cover for the highly secret technology. Thus, a true radar
system must both detect and provide range (distance) information for a target. Before 1934,
no single system gave this performance; some systems were Omni-directional and provided
ranging information, while others provided rough directional information but not range. A
key development was the use of pulses that were timed to provide ranging, which were sent
from large antennas that provided accurate directional information. Combining the two
allowed for accurate plotting of targets.
First military radars
During the 1930s, efforts to use radio echoes for aircraft detection were initiated
independently and almost simultaneously in eight countries that were concerned with the
prevailing military situation and that already had practical experience with radio technology.
The United States, Great Britain, Germany, France, the Soviet Union, Italy, the Netherlands,
and Japan all began experimenting with radar within about two years of one another and
embarked, with varying degrees of motivation and success, on its development for military
purposes. Several of these countries had some form of operational radar equipment in
military service at the start of World War II.
The first observation of the radar effect at the U.S. Naval Research Laboratory (NRL) in
Washington, D.C., was made in 1922. NRL researchers positioned a radio transmitter on one
shore of the Potomac River and a receiver on the other. A ship sailing on the river
unexpectedly caused fluctuations in the intensity of the received signals when it passed
between the transmitter and receiver. (Today such a configuration would be called bistatic
radar.) In spite of the promising results of this experiment, U.S. Navy officials were unwilling
to sponsor further work.
The principle of radar was “rediscovered” at NRL in 1930 when L.A. Hyland observed that
an aircraft flying through the beam of a transmitting antenna caused a fluctuation in the
received signal. Although Hyland and his associates at NRL were enthusiastic about the
prospect of detecting targets by radio means and were eager to pursue its development in
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earnest, little interest was shown by higher authorities in the navy. Not until it was learned
how to use a single antenna for both transmitting and receiving (now termed monostatic
radar) was the value of radar for detecting and tracking aircraft and ships fully recognized.
Such a system was demonstrated at sea on the battleship USS New York in early 1939.
The first radars developed by the U.S. Army were the SCR-268 (at a frequency of 205 MHz)
for controlling antiaircraft gunfire and the SCR-270 (at a frequency of 100 MHz) for
detecting aircraft. Both of these radars were available at the start of World War II, as was the
navy’s CXAM shipboard surveillance radar (at a frequency of 200 MHz). It was an SCR-270,
one of six available in Hawaii at the time, that detected the approach of Japanese warplanes
toward Pearl Harbor, near Honolulu, on December 7, 1941; however, the significance of the
radar observations was not appreciated until bombs began to fall.
Britain commenced radar research for aircraft detection in 1935. The British government
encouraged engineers to proceed rapidly because it was quite concerned about the growing
possibility of war. By September 1938 the first British radar system, the Chain Home, had
gone into 24-hour operation, and it remained operational throughout the war. The Chain
Home radars allowed Britain to deploy successfully its limited air defences against the heavy
German air attacks conducted during the early part of the war. They operated at about 30
MHz—in what is called the shortwave, or HF, band—which is actually quite a low frequency
for radar. It might not have been the optimum solution, but the inventor of British radar, Sir
Robert Watson-Watt, believed that something that worked and was available was better than
an ideal solution that was only a promise or might arrive too late.
The Soviet Union also started working on radar during the 1930s. At the time of the German
attack on their country in June 1941, the Soviets had developed several different types of
radars and had in production an aircraft-detection radar that operated at 75 MHz (in the very-
high-frequency [VHF] band). Their development and manufacture of radar equipment was
disrupted by the German invasion, and the work had to be relocated.
At the beginning of World War II, Germany had progressed farther in the development of
radar than any other country. The Germans employed radar on the ground and in the air for
defence against Allied bombers. Radar was installed on a German pocket battleship as early
as 1936. Radar development was halted by the Germans in late 1940 because they believed
the war was almost over. The United States and Britain, however, accelerated their efforts.
By the time the Germans realized their mistake, it was too late to catch up.
Except for some German radars that operated at 375 and 560 MHz, all of the successful radar
systems developed prior to the start of World War II were in the VHF band, below about 200
MHz. The use of VHF posed several problems. First, VHF beam widths are broad. (Narrow
beam widths yield greater accuracy, better resolution, and the exclusion of unwanted echoes
from the ground or other clutter.) Second, the VHF portion of the electromagnetic spectrum
does not permit the wide bandwidths required for the short pulses that allow for greater
accuracy in range determination. Third, VHF is subject to atmospheric noise, which limits
receiver sensitivity. In spite of these drawbacks, VHF represented the frontier of radio
technology in the 1930s, and radar development at this frequency range constituted a genuine
pioneering accomplishment. It was well understood by the early developers of radar that
operation at even higher frequencies was desirable, particularly since narrow beam widths
could be achieved without excessively large antennas.
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Advances during World War II
The opening of higher frequencies (those of the microwave region) to radar, with its attendant
advantages, came about in late 1939 when the cavity magnetron oscillator was invented by
British physicists at the University of Birmingham. In 1940 the British generously disclosed
to the United States the concept of the magnetron, which then became the basis for work
undertaken by the newly formed Massachusetts Institute of Technology (MIT) Radiation
Laboratory at Cambridge. It was the magnetron that made microwave radar a reality in World
The successful development of innovative and important microwave radars at the MIT
Radiation Laboratory has been attributed to the urgency for meeting new military capabilities
as well as to the enlightened and effective management of the laboratory and the recruitment
of talented, dedicated scientists. More than 100 different radar systems were developed as a
result of the laboratory’s program during the five years of its existence (1940–45).
One of the most notable microwave radars developed by the MIT Radiation Laboratory was
the SCR-584, a widely used gunfire-control system. It employed conical scan tracking—in
which a single offset (squinted) radar beam is continuously rotated about the radar antenna’s
central axis—and, with its four-degree beam width, it had sufficient angular accuracy to place
antiaircraft guns on target without the need for searchlights or optics, as was required for
older radars with wider beam widths (such as the SCR-268). The SCR-584 operated in the
frequency range from 2.7 to 2.9 GHz (known as the S band) and had a parabolic reflector
antenna with a diameter of nearly 6.6 feet (2 metres). It was first used in combat early in 1944
on the Anzio beachhead in Italy. Its introduction was timely, since the Germans by that time
had learned how to jam its predecessor, the SCR-268. The introduction of the SCR-584
microwave radar caught the Germans unprepared.
After the war, progress in radar technology slowed considerably. The last half of the 1940s
was devoted principally to developments initiated during the war. Two of these were the
monopulse tracking radar and the moving-target indication (MTI) radar. It required many
more years of development to bring these two radar techniques to full capability.
New and better radar systems emerged during the 1950s. One of these was a highly accurate
monopulse tracking radar designated the AN/FPS-16, which was capable of an angular
accuracy of about 0.1 milliradian (roughly 0.006 degree). There also appeared large, high-
powered radars designed to operate at 220 MHz (VHF) and 450 MHz (UHF). These systems,
equipped with large mechanically rotating antennas (more than 120 feet [37 metres] in
horizontal dimension), could reliably detect aircraft at very long ranges. Another notable
development was the klystron amplifier, which provided a source of stable high power for
very-long-range radars. Synthetic aperture radar first appeared in the early 1950s, but it took
almost 30 more years to reach a high state of development, with the introduction of digital
processing and other advances. The airborne pulse Doppler radar also was introduced in the
late 1950s in the Bomarc air-to-air missile.
The decade of the 1950s also saw the publication of important theoretical concepts that
helped put radar design on a more quantitative basis. These included the statistical theory of
detection of signals in noise; the so-called matched filter theory, which showed how to
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configure a radar receiver to maximize detection of weak signals; the Woodward ambiguity
diagram, which made clear the trade-offs in waveform design for good range and radial
velocity measurement and resolution; and the basic methods for Doppler filtering in MTI
radars, which later became important when digital technology allowed the theoretical
concepts to become a practical reality.
The Doppler frequency shift and its utility for radar were known before World War II, but it
took years of development to achieve the technology necessary for wide-scale adoption.
Serious application of the Doppler principle to radar began in the 1950s, and today the
principle has become vital in the operation of many radar systems. The Doppler frequency
shift of the reflected signal results from the relative motion between the target and the radar.
Use of the Doppler frequency is indispensable in continuous wave, MTI, and pulse Doppler
radars, which must detect moving targets in the presence of large clutter echoes. The Doppler
frequency shift is the basis for police radar guns. SAR and ISAR imaging radars make use of
Doppler frequency to generate high-resolution images of terrain and targets. The Doppler
frequency shift also has been used in Doppler-navigation radar to measure the velocity of the
aircraft carrying the radar system. The extraction of the Doppler shift in weather radars,
moreover, allows the identification of severe storms and dangerous wind shear not possible
by other techniques.
The first large electronically steered phased-array radars were put into operation in the 1960s.
Airborne MTI radar for aircraft detection was developed for the U.S. Navy’s Grumman E-2
airborne-early-warning (AEW) aircraft at this time. Many of the attributes of HF over-the-
horizon radar were demonstrated during the 1960s, as were the first radars designed for
detecting ballistic missiles and satellites.
Radar in the digital age
During the 1970s digital technology underwent a tremendous advance, which made practical
the signal and data processing required for modern radar. Significant advances also were
made in airborne pulse Doppler radar, greatly enhancing its ability to detect aircraft in the
midst of heavy ground clutter. The U.S. Air Force’s airborne-warning-and-control-system
(AWACS) radar and military airborne-intercept radar depend on the pulse Doppler principle.
It might be noted too that radar began to be used in spacecraft for remote sensing of the
environment during the 1970s.
Over the next decade radar methods evolved to a point where radars were able to distinguish
one type of target from another. Serial production of phased-array radars for air defence (the
Patriot and Aegis systems), airborne bomber radar (B-1B aircraft), and ballistic missile
detection (Pave Paws) also became feasible during the 1980s. Advances in remote sensing
made it possible to measure winds blowing over the sea, the geoids (or mean sea level), ocean
roughness, ice conditions, and other environmental effects. Solid-state technology and
integrated microwave circuitry permitted new radar capabilities that had been only academic
curiosities a decade or two earlier.
Continued advances in computer technology in the 1990s allowed increased information
about the nature of targets and the environment to be obtained from radar echoes. The
introduction of Doppler weather radar systems (as, for example, Nexrad), which measure the
radial component of wind speed as well as the rate of precipitation, provided new hazardous-
weather warning capability. Terminal Doppler weather radars (TDWR) were installed at or
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near major airports to warn of dangerous wind shear during takeoff and landing. Unattended
radar operation with little downtime for repairs was demanded of manufacturers for such
applications as air traffic control. HF over-the-horizon radar systems were operated by
several countries, primarily for the detection of aircraft at very long ranges (out to 2,000
nautical miles [3,700 km]). Space-based radars continued to gather information about the
Earth’s land and sea surfaces on a global basis. Improved imaging radar systems were carried
by space probes to obtain higher-resolution three-dimensional images of the surface of
Venus, penetrating for the first time its ever-present opaque cloud cover.
The first ballistic missile defence radars were conceived and developed in the mid-1950s and
1960s. Development in the United States stopped, however, with the signing in 1972 of the
antiballistic missile (ABM) treaty by the Soviet Union and the United States. The use of
tactical ballistic missiles during the Persian Gulf War (1990–91) brought back the need for
radars for defence against such missiles. Russia (and before that, the Soviet Union)
continually enhanced its powerful radar-based air-defence systems to engage tactical ballistic
missiles. The Israelis deployed the Arrow phased-array radar as part of an ABM system to
defend their homeland. The United States developed a mobile active-aperture (all solid-state)
phased-array called Theater High Altitude Area Defence Ground Based Radar (THAAD
GBR) for use in a theatre wide ABM system.
Advances in digital technology in the first decade of the 21st century sparked further
improvement in signal and data processing, with the goal of developing (almost) all-digital
phased-array radars. High-power transmitters became available for radar application in the
millimetre-wave portion of the spectrum (typically 94 GHz), with average powers 100 to
1,000 times greater than previously.
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Basic Principal of Operation
The principal of operation of primary radar is easy but the theory can be quite complex. The
radar consist of many disciplined component’s such as mixture of heavy mechanical,
electrical high power microwave engineering, and advanced high speed signal and data
processing techniques. Radar generates EM waves thorough oscillating electrical current
arrangement that causes the voltage to goes up and down at certain Frequency and thus
electricity produces Electromagnet energy, that later transmitted in the sky as an continual
pulse form in an guided directions. The electromagnetic waves are reflecting in nature when
they meet an electrically leading surface, when these waves get reflected back and received
by the receiving antenna. The received waves are weaker, so in order to get the appropriate
frequency they get amplified and calibrated and thus and converted into visible form by
means of a cathode-ray tube. Electromagnetic energy travels in air at a constant speed,
approx. to speed of light around 300,000 Kilometers per second.
The timer originate the pulses and transmitter converts it into Radio Frequency Energy (R.F
Radiation) and following that Transmitting antenna’s flung that energy into sky. But at all the
same time timer sends part of each energy pulse to the indicator where it starts to sweep the
base line. The main pip at the beginning of the base line is formed when part of energy
leaving the transmitter antenna, picked up by the sensitive receiver. The base line is
synchronized with the outgoing pulse and provides us with an accurate electronic yard stick
for measuring the distance travelled by each pulse. When a target comes within range echo
signals are reflected. “These returning signals are picked up the receiving antennas” and
thereby amplified by receiver and finally registered on the base line of indicator as a target
The position of the target pick at a base line is calibrated by the set and in that way you find
the range of the target. Each Set’s transmits high frequency radio energy in the form of short
pulses. Followed by a listening period, one long enough to permit a target echo to return from
the maximum range. In that way echo signal can be seen clearly by themselves. To make sure
that proper time interval are maintained and at, this intervals each unit is triggered of the time
accuracy of 1 Millionth
of the second. Every set is equipped with master time piece called a
timer or some time synchronizer.
Heart of timer is known as Klystron or sometimes in simple terms called Vacuum Tube. First
they generate the sine wave each cycle is identical to all cycles. For example if the cycle
frequency is 1000 cycles/sec, we actually say 1 Sec = 1000 equal parts. In this wave
formation it’s almost impossible to tell from where the each 1000 cycle begin and end. So to
make this easier it is changed in peak wave. This can be measured from the positive peak to
the positive peak. This wave is the basic controlling wave of the set. All the component
actions of Radar are synchronized with these peaks. For instance this part of peak wave that
passes form timer to the indicator to trigger off the base line synchronies the base line with,
outgoing pulse because the same time the same peak wave triggers a pulse forming circuit.
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This creates a new wave form, pulses with flat top. We notice that throughout these changes
the exact Sub-division of second and time have not lost. We still got the precisely same
numbers of positive peaks per seconds. That are original sine wave did. Main difference of
Sine Wave & Digital Signal Wave are that, in the original sine wave the voltage rises and falls
gradually, the action is easy but never sudden. But when we use Digital Signal Wave, it
triggers pulse and the voltage rises from zero to its peak value instantly. Remains it at that
point till the length of the pulse duration then immediately returns to zero. “Pulse duration is
also called pulse width.”
This action of trigger pulse, cause sudden powerful burst of energy to be generated and
transmitted. Then with equal suddenness the energy is turned OFF while the outbound pulse
travels to space this transmission of radio energy may last to half a microsecond to several
microsecond then goes OFF to several thousand microseconds. ON AGAIN, OFF AGAIN.
As a distinct pip, but as the target come closer to the set the echo pip on the base line
approach and may even merge. In the long range radar sets, we didn’t need to worry about the
merging problem as they turn the target over the short range sets. But to track short range
target effectively we must keep the target pip from merging with the main band.
That’s why short range sets must transmit narrow pulses or pulses of short durations. With
this type of pulse, set will get a distinct and a separate echo pip on the base line even at an
extremely short range. We can conclude therefore that the width of the pulse largely
determine the effective minimum range of the set. Now we examine the time interval between
there pulses. This time interval or listening period must cover the time it takes for an up-
going pulse to reach a target at a maximum range and return. For a set designed to maximum
range 20 miles. Then the timer might get to generate approx. 4000 pulses per second. But if
the desired maximums range of the set is 100 miles, then the listening period has to be longer.
And the timer might have to generate not more than 900 pulses per second. We can see that
the basic concept to determine the maximum range of the set is the fixed rate of pulse
repetition, it’s known as Pulse repetition frequency (PRF). The width of each pulse or pulse
duration primarily stabilizes the set’s minimum range. Well the no. of pulses it transmits per
second, PRF largely determines the maximum range. Timer controls both pulses width and
PRF. They vary greatly in size and construction. Once a timer generated a voltage wave and
it’s been shaped in desired rectangular pulse. The transmitter ready to take over, he uses the
voltage energy receives from the timer to trigger off the radio frequency oscillator which may
be one or more high powered tubes.
This is the most important component in the transmitter; it is here the set generates the
powerful pulses of R.F energy which is flung into the space by antenna. This oscillator tube
handles the extremely high voltages and requires strong source of energy to make it function.
The voltage pulse as it now stands, although its right shape isn’t strong enough to trigger the
oscillator tube. So the transmitter uses a driver and modulator to amplify the voltage it
receives in driver the pulse reproduced and amplified, the pulse is further amplified by the
modulator, now it’s ready to trigger the R.F energy that will be transmitted in other word, it
act as an switch for the R.F oscillator. When this oscillator is triggered by an amplified
voltage pulse, it oscillates at very high frequency 100 of Mega Cycles per second. For the
length of time of pulse duration, the period when, its length is depend on PRF stabilized by
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This PRF also determine the exact micro second when the tube will again to oscillates
whatever the size and shape of the transmitter the job it does is essentially the same
amplifying the voltage pulse until it’s strong enough the trigger the oscillator. The oscillator
then generates the R.F energy. Once the high frequency Radio Pulses leave the transmitter,
they are carried by the system of transmitter line to the antenna. There are many types of
transmission lines, parallel two wire conductor coaxial lines, wave guides and many
arrangement but there purposes is the same.
The power Pr returning to the receiving antenna is given by the equation:
Pt = transmitter power
Gt = gain of the transmitting antenna
Ar = effective aperture (area) of the receiving antenna
σ = radar cross section, or scattering coefficient, of the target
F = pattern propagation factor
Rt = distance from the transmitter to the target
Rr = distance from the target to the receiver.
In the common case where the transmitter and the receiver are at the same
location, Rt = Rr and the term Rt² Rr² can be replaced by R4
, where R is the range. This yields:
This shows that the received power declines as the fourth power of the range, which means
that the received power from distant targets is relatively very small.
Additional filtering and pulse integration modifies the radar equation slightly for pulse-
Doppler radar performance, which can be used to increase detection range and reduce
The equation above with F = 1 is a simplification for transmission in a vacuum without
interference. The propagation factor accounts for the effects of multipath and shadowing and
depends on the details of the environment. In a real-world situation, pathloss effects should
also be considered.
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2. Remote Sensing
3. Air Traffic Control
4. Law Enforcement and Highway Security
5. Aircraft Safety and Navigation
6. Ship Safety
8. Miscellaneous Application
i. GPR Applications
ii. HHR Applications
iii. Day to Day Applications
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Important Part of Air Defence System, Operation of Offensive Missiles & Other
Target Detection, Target Tracking & Weapon Control
Tracks the Targets, Directs the Weapon to an Intercept and Assess the Effectiveness of
Also used in Area, Ground and Air Surveillance.
Below Ground Probing
Mapping of Sea Ice
Air Traffic Control:
Used to safely control air traffic in the vicinity of the airports and enroute
Ground vehicular traffic & aircraft taxing
Mapping of regions of rain in the vicinity of airports & weather
Law Enforcement and Highway Safety:
Radar speed meters are used by police for enforcing speed limits
It is used for warning of pending collision, actuating air bag or warning of obstruction
or people behind a vehicle or in the side blind zone
Aircraft Safety and Navigation:
Airborne weather avoidance radar outlines the regions of precipitation & dangerous
Low flying military aircrafts rely on terrain avoidance & terrain following radars to
avoid collision with high terrain & obstructions.
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Radar is found on ships & boats for collision avoidance & to observe navigation
buoys, when the visibility is poor
Shore based radars are used for surveillance of harbours & river traffic.
Space vehicles have used radar for clocking & for landing on the moon
Used for planetary exploration
Ground based radars are used for detection & tracking of satellites & other space
Used for radio astronomy.
1. It is used for non-contact measurement of speed & distance.
2. Used for oil & gas exploration.
3. Used to study movements of insects & birds.
GPR & HHR Applications:
Shallow GPR surveys
1. Locate pipes and utilities
2. Buried objects
3. Cemetery & Grave location
Deep GPR surveys
1. Landfill & trench delineation
2. Bedrock depth studies
3. Sink hole location
1. Security & border surveillance
2. Under ground, through-wall &
3. Automotive safety, including
collision-avoidance & intelligent
4. “smart” device such as lights,
heaters & tools that
automatically turn on or off
5. Medical diagnostics
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Day to Day Application:
Micropower impulse radar sensors used in proximity fuses have been successfully tested.
The fuses trigger small bombs to detonate at about 1 meter from the ground.
A Life Saver:
Livermore engineering technologist used a micropower impulse radar sensor attached to
an extender to search for trapped people through rubble at ground zero of the world trade
center following the September 11, 2001, terrorist attacks.
A) The HERMES (high-performance electromagnetic roadway mapping and evaluation
system) bridge inspector is a radar-based sensing system mounted in a trailer.
(b) The array of 64 radar modules located beneath the trailer produces images of the
insides of bridge decks.
(c) This image shows a suspect area where a delamination in the concrete may have
This vehicle tows the Antenna Transceiver Group (ATG) with the integrated modular
azimuth positioning system (maps) mounted on the trailer. This is controlled by an
operator either located within the shelter or remotely located.
Tunnel Wall Inspection:
Locating Underground Pipes:
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1. Professional cameras for face detection:
Nowadays people are aware of the need of vehicle security due to the fact that they
are various cases of car robbery. Therefore it is incumbent upon us to increase the
level of securities. To make the system more secure, the system is recommended to
integrate with face detection. This is means instead of identifying driver with their
plate, it also important to identify by her or his face.
We can do this by using a professional camera that contain a face detect applications,
nowadays there are growing number of digital cameras now include a Face
Recognition mode. The camera detects faces in a scene and then automatically
focuses (AF) and optimizes exposure (AE).
2. Professional camera to upgrade the image quality:
We want to use more professional cameras to improve the image quality to be easier
to recognize the plate numbers.
3. Location of the camera:
The camera to vehicle distance around 40 feet. This system is able to detect license
plate area for all the vehicles. We want to put the camera in the middle of the road to
be able to detect any vehicles.
Creating a database of the system:
We use to create a data base for all the cars plate numbers and their owner identity.
We use SQL to create a database for the car plate number and the name of the owner
and his penalty.
After building the database system and detecting the license plate numbers, we will
use these numbers to compare it with the data base elements to extract the car owner’s
telephone number. After that we will use a software program to send an automatic
SMS to the car owner to inform him that he has been crossed the limit speed.
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The US has radar able to track an object the size of a baseball from San
Francisco to Virginia!
Ever wonder whether a hostile enemy could successfully hit our soil with a missile? If a war
were to occur it could be a very likely threat, yet the probability of it being successful is very
This is thanks to new technologies such as the Sea-based X-band Radar system that has been
put in place at Adak Island, Alaska. This radar system is so powerful that it could track
virtually any moving object anywhere in America.
This means that if a missile were to be sent at American soil, the X-Band would most likely
see it long in advance. X-Band radars operate on a wavelength of 2.5-4 cm and are often used
to detect such tiny objects as water particles and light!
Although the X-Band frequency is usually used for determining future weather, it is has now
been engineered for military purposes.
Doppler Radar Facts
Meteorologists use a device called Doppler radar to predict the weather. Without Doppler
radar, we probably wouldn't be able to receive severe storm warnings and tornado warnings
in advance. Thanks to modern technology, Doppler radar is capable of measuring
precipitation patterns and determining whether a storm will be severe.
What is Doppler Radar?
Doppler radar measures Doppler shift in a radar beam. The beam is reflected based on an
object's motion. The "Doppler effect" is used in radars in order to detect thunderstorms or
tornadoes. Based on the extent of the red and blue shifts, angular velocity can be calculated.
This measures precipitation patterns and is also capable of determining the severity of storms
and whether a tornado is likely to develop in the general area.
Christian Doppler, an Austrian physicist, proposed the "Doppler effect" in 1842. The Doppler
effect is the apparent change in frequency of a wave for the person observing the moving
source of the wave. For example, if an ambulance is coming toward you while it's far away, it
sounds quiet. As it approaches, it gets louder. Once it passes by, the frequency is identical to
the emitted frequency, and as it leaves, the frequency gets lower.
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Space Radar Facts
With zero fanfare, the U.S. Air Force recently revised its fact sheet on the Space Radar,
which became defunct in 2008, at least to the public eye. The revised fact sheet states that the
program is envisioned as a constellation of nine satellites "providing worldwide coverage"
and yielding five kinds of surveillance products: synthetic aperture radar imagery; surface
moving target indication—both ground and ocean target movement detection and
identification; open-ocean surveillance to detect ships; high-resolution terrain information,
yielding 3-D topographic maps; and "advanced products" in the realm of geospatial
intelligence. The Space Radar will provide enhanced global deterrence "through the mere
threat of observation," states the document, posted in late February.
The Problem with Police Radar
In early 1979, a Miami television station showed viewers a radar gun clocking a palm tree at
86 mph and a house at 28 mph. In the first instance, the reading was caused by panning the
radar antenna and in the second, the radar unit was measuring the fan motor in the patrol car.
The TV report prompted a court case that brought radar errors national attention. A year later
the National Bureau of Standards tested the six most popular police radar models, finding that
all produced false speed readings in the presence of CB or police radios. Each of the two-
piece units produced panning errors like the one that caught the Miami house apparently
moving at 28 mph. All of the moving radar units were subject to "shadowing," causing some
of the patrol car’s speed to be added to that of the target vehicle (Federal Register, Vol. 46,
No. 5, Jan. 8, 1981).
Radar works on the Doppler principal of frequency shift. The same way a train whistle
changes pitch as it approaches then passes by you. By measuring the change in pitch the
speed of the object can be measured. To cut costs, police radar uses comparatively
inexpensive components and its operation is kept as simple as possible. To that end police
radar share the following characteristics:
1) Low power emitter to keep the operator and the general public safe from microwave
2) Displays only the strongest reflected signal.
3) Relies on the operator’s skill to determine the speed and error correction.
4) None of the units in service follow a government standard for reliability or
performance. i.e. Your taking the word of the manufacturer, that the unit performs as
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eHow.com (What Does RADAR Mean?)
Merrill I. Skolnik (ed.), Radar Handbook, 2nd ed. (1990)
S.S. Swords, Technical History of the Beginnings of Radar (1986)
Henry E. Guerlac, Radar in World War II, 2 vol. (1987)
Traffic safety and accident table.
Ekco Radar WW2 Shadow Factory The secret development of British radar.
ES310 "Introduction to Naval Weapons Engineering.". (Radar fundamentals section)
Hollmann, Martin, "Radar Family Tree". Radar World.
Penley, Bill, and Jonathan Penley, "Early Radar History—an Introduction". 2002.
Pub 1310 Radar Navigation and Maneuvering Board Manual, National Imagery and
Mapping Agency, Bethesda, MD 2001 (US govt publication '...intended to be used
primarily as a manual of instruction in navigation schools and by naval and merchant
Swords, Seán S., "Technical History of the Beginnings of Radar", IEE History of
Technology Series, Vol. 6, London: Peter Peregrinus, 1986.
Some External Links.
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MIT Video Course: Introduction to Radar Systems A set of 10 video lectures
developed at Lincoln Laboratory to develop an understanding of radar systems
Popular Science, August 1943, What Are the Facts About RADAR one of the
first detailed factual articles on radar history, principles and operation
published in the US
"The Great Detective", 1946. Story of the development of radar by the
The short film Radar and Its Applications (1962).
The Indian Air Force Museum, Palam, is the museum of the Indian Air
Force, located at the Palam Air Force Station in Delhi, India.