RADAR

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP92B00181R000400330013-7
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 4
• Document Creation Date: December 23, 2016
• Document Release Date: January 30, 2013
• Sequence Number: 13
• Content Type: MISC

Declassified in Part - Sanitized Copy Approved for Release 2013/01/30: CIA-RDP92B00181 R000400330013-7 25X1
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Radio waves can be used for purposes other than communicating
between two distant points. By means of radio wave reflections,
or echoes, from distant objects it is possible to accurately
determine the distance to the object, its relative position, and
its speed and direction of travel (if moving). Radar--Radio
Detection and Ranging--was an experimental curiosity in the
1930's, but was pressed into wartime service in the 1940's, where
it quickly provided the critical service of aircraft and ship
detection. By the end of World War 2, radar technology had.
advanced to the point where radar had become vital to all ground,
ship, and air operations. Following the war, many civil
applications were found for radar, primarily air traffic control,
air navigation, ship navigation, weather monitoring, ground
mapping, and spacecraft operations. Other applications include
search and rescue, iceberg patrol, and altimeters. Military
applications are so pervasive today, that all weapons platforms
rely on radars, other sensors, and their accompanying computer
processing to protect themselves and to detect and attach the
enemy.
The technology to perform these functions has evolved from a
simple pulsed radar to the advanced multimode, doppler radar
capable of precision tracking of multiple targets. Simple pulsed
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radars usually had antennas that moved mechanically to position
the radiated beam, only had visual displays for the operator to
view, and were generally stand-alone units not integrated with
other systems. The modern multimode radar, under digital
computer control, can automatically switch between general
surveillance, target acquisition, target track, missile guidance,
and navigation mode. Doppler refers to the shift in the radio
frequency of the signal returned from a target that is moving;
the processing of such a signal provides a powerful capability to
discriminate and characterize a moving target, especially a small
target "hidden" in a background of ground clutter and noise.
Modern radars usually have array antennas, which means no
mechanical motion, only an electronic repositioning of the beam.
A variety of displays, both pictorial and numeric, are available,
and the system is usually computer-coupled into the other major
systems of the platform, ie; fire control and navigation.
Industry leaders in radar design and manufacturing are found
in West Europe and the US. British, Dutch, Swedish, Italian, and
French radars are excellent by modern standards. They are being
marketed world-wide, including NATO, other developed countries,
and many developing nations. Civilian versions of military
radars, such as airport control radars, merchant ship navigation
radars, harbor surveillance, weather radars, ground mapping,
geodetic survey, and spacecraft control, are widely sold. US
manufacturers participate heavily in this market, of course.
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Military radars are vulnerable to attack by modern "smart"
weapons designed to home on the transmitted radar signal, which
acts as a powerful beacon. They are also vulnerable to
electronic countermeasures designed to confuse or disrupt the
radar. Numerous techniques have been developed to reduce these
problems, such as reducing the ON time, adaptive adjustment of
the antenna pattern, reducing transmitted power, or modifying the
signal waveform itself to provide some immunity to jamming or
deceptive practices. The radar's own integrated computerized
processor will often recognize a.developing problem, and
automatically initiate an action to counter the debilitating
effect.
The basic technical trends being incorporated into modern
radars fall into the following categories:
a. Comprehensive processing to extract all possible
information from the returned,signals.' Digital
computers, optical processing devices, and advanced
mathematical alogrithms are the key to these processors.
b. Attempts to "reduce the signature", or develop a quiet
radar, are directed toward the stealth programs and
other efforts that require covertness. To reduce peak
power, yet maintain the average power, continuous wave
(CW) signals or extremely fast pulse rate signals are
employed. Such techniques can reduce the power by a
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factor of 1000 or more, without sacrificing performance.
This reduced power greatly protects a radar from enemy
detection.
c. Jam-resistent features, such as frequency hopping and
spread spectrum coding, are extremely complex
modifications to the signal waveform for the purpose of
overcoming interfering signals. This is a new, but very
promising, technology and is not widely implemented at
present, but the technology is available world-wide.
d. Small size and low weight are premium features for
modern radars. Many airborne and spaceborne
applications benefit from these features, but the most
stringint need for miniaturization is in aerodynamic,
tactical missiles having self-contained radar guidance
systems. These radars usually operate at higher
frequencies, such as EHF or optical.
Most modern electronic equipment, including radars, are
specifically designed for easy maintenance by low-skill
technicians. Modular packaging, plug-in units, and automated
diagnostic checks simplify the process of repair. Therefore,
many countries that lack a highly skilled work force are able to
effectively use advanced electronic equipment in their armed
forces. The result is that LDC's can frequently maintain a
military capability level well above what might otherwise be
expected.
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