MiG-29
Banned Idiot
Before discussing passive radar, several
other radar and sensor systems are worth
mentioning in terms of counterstealth capability.
One of the most significant counters
to stealth, namely conventional very high
frequency (VHF) and ultra high frequency
(UHF) radar, has been around since World
War II and is still in use today for long-range
air surveillance. Most LO techniques are
designed to defeat acquisition and fire control
radar in the X band, which uses centimeter
wavelength. VHF- and UHF-band radar,
however, uses decimeter- to meter-long
wavelength. In general, the RCS of an aircraft
increases as wavelength of the illuminating
radar increases.30 Furthermore, when the
radar wavelength is in the same order of magnitude
as the aircraft or parts of it, the radar
waves and the aircraft resonate, which significantly
increases the RCS of the aircraft.31 It
is the physics of longer wavelength and resonance that enables VHF and UHF radar to
detect stealth aircraft. Poor resolution in angle
and range, however, has historically prevented
these radars from providing accurate targeting
and fire control.32
Since the Gulf War, the Russian defense
radar industry has put considerable effort into
digitizing its VHF and UHF radar systems
to improve counterstealth capability. Russia’s
older model radars now have improved resolution
and signal processing, and newly developed
models, such as the Nebo surface vehicle
unit, which is a VHF adaptive electronically
steered array radar, likely present significant
counterstealth capability.33
Other recently developed conventional
radars likely to have counterstealth capability
include Lockheed Martin’s theater highaltitude
area defense radar and the Israeli
Green Pine radar (recently sold to India),
systems with both long range and high
resolution in the UHF L-band.34 The SignalThe Signal
Multi-beam Acquisition Radar for Tracking
(L) naval radar manufactured by Thales is
yet another system with reputed counterstealth
capability.35
Passive listening systems, such as electronic
support measures (ESM) and direction
finding (DF), attempt to detect stealth
aircraft radar, radio, and data link emissions
and pass this information to surveillance
radars. LPI techniques of stealth are designed
to reduce or deny ESM and DF, but systems
such as the Russian Kolchuga remain formidable
threats that are likely being updated
with digital processing.36
Another counter to stealth is IR/electrooptical
(EO) systems, which include IR search
and track and high magnification optics. Such
systems, however, are limited in the ability
to scan large volumes of airspace and usually
must be cued by other sensors. In addition,
most of this spectrum is degraded by clouds,
low illumination, and low visibility. Stealth
aircraft counter IR/EO through heat signature
management, stealthy flight profiles, and LO
paint schemes.
Growing in potential as a counterstealth
technology is millimeter wave (MMW)
imaging, which uses the radiometric signature
naturally emitted by all objects. MMW
penetrates clouds and low visibility. The waveform
can also be transmitted by radar, which
then receives and processes the return echo.
The A–64 Apache Longbow/Hellfire system
is an example of operational MMW radar.
The Russian defense industry has developed MMW antiair missile seekers, and other
countries are following suit.37
While the aforementioned technologies
offer important capabilities, they possess
limitations that restrict their effectiveness
for air defense. Conventional radar is vulnerable
to detection and attack by electronic
warfare and air-delivered weapons; listening
systems do not provide tracking information;
and IR/EO/MMW is limited in surveillance
capabilities.
In contrast, passive radar is covert, all
weather, and capable of medium- to longrange
surveillance, and shows strong potential
in detecting, tracking, and targeting stealth
aircraft. It is thus emerging as a solid competitor
in the counterstealth game.
Passive Radar
A new paradigm is emerging, enabled by
advances in networked computing and passive
radar technology. Because of their potential to
counter stealth-based airpower advantage, the
use of these technologies by peer competitors
is highly likely. That these systems are both
low cost and, in part, based on commercialoff-
the-shelf technology makes them attractive
for nonpeer countries as well.
Passive radars use transmitters of
opportunity. Potential waveforms include FM
and AM radio, television, digital audio/video
broadcast, and cellular phone networks.38
Today, passive radar is often configured as
a “multistatic” system using three or more
transmitters and receivers.Passive radar locates and tracks targets
through a combination of methods, greatly
simplified here for the sake of discussion.
First, the radar measures the time difference
of arrival between the direct signal from the
transmitter and the reflected signal from the
target to determine the bistatic range. Bistatic
The meeting of wavelengths between radar and aircraft causes resonation between the two, significantly raising an aircraft's reflection in the radar spectrum, making it much more visible. VHF radar has been incorporated into the Russian military's 1L119 Nebo SVU, its first VHF-band active electronically steered array (AESA); although detailed analysis of this vehicle-mounted array, Russian sources report it has achieved excellent results in spotting stealth aircraft.
The asymmetric dimension to future Russian air warfare programs entails the development of counter very-low-observable (CVLO) radar technologies and long-range, high-speed surface-to-air missile (SAM) designs, complemented by a new generation of short-range point defense weapons intended to destroy incoming guided weapons, especially anti-radiation missiles, cruise missiles and guided bombs. All systems are built for high mobility, typically with 5-min. “shoot and scoot” times to permit “scooting” inside of the targeting and engagement cycles of most guided munitions.
The focus in Russian CVLO radar has been in the 1-meter VHF band. Stealth shaping in fighters is largely ineffective in VHF because components such as stabilizers and wingtips have dimensions close to the radar wavelength. Radar-absorbent treatments developed for S-band and above are ineffective in VHF due to both electrical behavior and thickness. The flagship product is the NNIIRT/Almaz-Antey 55Zh6M Nebo M 3-D radar system, of which 100 were recently ordered to re-equip Russian air defense forces. The Nebo M is uniquely a “multi-band” design, comprising three radars and a central data fusion and command post module, all carried on separate high-mobility 8 x 8 24-ton vehicles. The Nebo-SVU was credited with space-time adaptive processing technology similar to that or the Northrop Grumman E-2D Hawkeye, and in 2002 NNIIRT's Igor Krylov said “We can see the stealth [F-117A] as clearly as any other plane”.
Advances in processing power may enable better tracking systems for long-wavelength radars that reduce the historical LO technology advantage. We know very high frequency (VHF), and ultra-high frequency (UHF) long-range air defense radars can see stealth aircraft at great distances, because LO techniques are targeted towards X-band target-tracking radar systems.28 As the longer wavelength reflects off an aircraft, it significantly increases the Radar Cross Section (RCS), which enables VHF and UHF radars to detect stealth aircraft at further distances than fire-control X-band radars.
New Russian models like the Nebo surface vehicle unit, a VHF adaptive electronically steered array radar, likely presents a significant counter-stealth capability. By 2035 other technology advances could leverage this capability.
Another counter-stealth technology is Passive Coherent Location (PCL).
Currently many countries are fielding PCL radar systems such as the Russian VERA-E, which is said to be the only system that can detect the B-2
РЛС «Небо-СВУ» (1Л119)
Радиолокационная станция «Небо-СВУ» (1Л119) предназначена для автоматического обнаружения, измерения координат и сопровождения широкого класса современных воздушных объектов: самолетов стратегической и тактической авиации, авиационных ракет типа «АСАЛМ», малоразмерных целей, малозаметных целей, в частности, выполненных по технологии «СТЕЛС»
Radar "Sky-SVU" (1L119)
Radar "Sky-SVU" (1L119) is designed to automatically identify, coordinate measuring and tracking a broad class of modern aircraft include aircraft strategic and tactical aircraft, aircraft missiles "ASALM" small targets, stealth targets, in particular, made by technology "Stealth"
other radar and sensor systems are worth
mentioning in terms of counterstealth capability.
One of the most significant counters
to stealth, namely conventional very high
frequency (VHF) and ultra high frequency
(UHF) radar, has been around since World
War II and is still in use today for long-range
air surveillance. Most LO techniques are
designed to defeat acquisition and fire control
radar in the X band, which uses centimeter
wavelength. VHF- and UHF-band radar,
however, uses decimeter- to meter-long
wavelength. In general, the RCS of an aircraft
increases as wavelength of the illuminating
radar increases.30 Furthermore, when the
radar wavelength is in the same order of magnitude
as the aircraft or parts of it, the radar
waves and the aircraft resonate, which significantly
increases the RCS of the aircraft.31 It
is the physics of longer wavelength and resonance that enables VHF and UHF radar to
detect stealth aircraft. Poor resolution in angle
and range, however, has historically prevented
these radars from providing accurate targeting
and fire control.32
Since the Gulf War, the Russian defense
radar industry has put considerable effort into
digitizing its VHF and UHF radar systems
to improve counterstealth capability. Russia’s
older model radars now have improved resolution
and signal processing, and newly developed
models, such as the Nebo surface vehicle
unit, which is a VHF adaptive electronically
steered array radar, likely present significant
counterstealth capability.33
Other recently developed conventional
radars likely to have counterstealth capability
include Lockheed Martin’s theater highaltitude
area defense radar and the Israeli
Green Pine radar (recently sold to India),
systems with both long range and high
resolution in the UHF L-band.34 The SignalThe Signal
Multi-beam Acquisition Radar for Tracking
(L) naval radar manufactured by Thales is
yet another system with reputed counterstealth
capability.35
Passive listening systems, such as electronic
support measures (ESM) and direction
finding (DF), attempt to detect stealth
aircraft radar, radio, and data link emissions
and pass this information to surveillance
radars. LPI techniques of stealth are designed
to reduce or deny ESM and DF, but systems
such as the Russian Kolchuga remain formidable
threats that are likely being updated
with digital processing.36
Another counter to stealth is IR/electrooptical
(EO) systems, which include IR search
and track and high magnification optics. Such
systems, however, are limited in the ability
to scan large volumes of airspace and usually
must be cued by other sensors. In addition,
most of this spectrum is degraded by clouds,
low illumination, and low visibility. Stealth
aircraft counter IR/EO through heat signature
management, stealthy flight profiles, and LO
paint schemes.
Growing in potential as a counterstealth
technology is millimeter wave (MMW)
imaging, which uses the radiometric signature
naturally emitted by all objects. MMW
penetrates clouds and low visibility. The waveform
can also be transmitted by radar, which
then receives and processes the return echo.
The A–64 Apache Longbow/Hellfire system
is an example of operational MMW radar.
The Russian defense industry has developed MMW antiair missile seekers, and other
countries are following suit.37
While the aforementioned technologies
offer important capabilities, they possess
limitations that restrict their effectiveness
for air defense. Conventional radar is vulnerable
to detection and attack by electronic
warfare and air-delivered weapons; listening
systems do not provide tracking information;
and IR/EO/MMW is limited in surveillance
capabilities.
In contrast, passive radar is covert, all
weather, and capable of medium- to longrange
surveillance, and shows strong potential
in detecting, tracking, and targeting stealth
aircraft. It is thus emerging as a solid competitor
in the counterstealth game.
Passive Radar
A new paradigm is emerging, enabled by
advances in networked computing and passive
radar technology. Because of their potential to
counter stealth-based airpower advantage, the
use of these technologies by peer competitors
is highly likely. That these systems are both
low cost and, in part, based on commercialoff-
the-shelf technology makes them attractive
for nonpeer countries as well.
Passive radars use transmitters of
opportunity. Potential waveforms include FM
and AM radio, television, digital audio/video
broadcast, and cellular phone networks.38
Today, passive radar is often configured as
a “multistatic” system using three or more
transmitters and receivers.Passive radar locates and tracks targets
through a combination of methods, greatly
simplified here for the sake of discussion.
First, the radar measures the time difference
of arrival between the direct signal from the
transmitter and the reflected signal from the
target to determine the bistatic range. Bistatic
The meeting of wavelengths between radar and aircraft causes resonation between the two, significantly raising an aircraft's reflection in the radar spectrum, making it much more visible. VHF radar has been incorporated into the Russian military's 1L119 Nebo SVU, its first VHF-band active electronically steered array (AESA); although detailed analysis of this vehicle-mounted array, Russian sources report it has achieved excellent results in spotting stealth aircraft.
The asymmetric dimension to future Russian air warfare programs entails the development of counter very-low-observable (CVLO) radar technologies and long-range, high-speed surface-to-air missile (SAM) designs, complemented by a new generation of short-range point defense weapons intended to destroy incoming guided weapons, especially anti-radiation missiles, cruise missiles and guided bombs. All systems are built for high mobility, typically with 5-min. “shoot and scoot” times to permit “scooting” inside of the targeting and engagement cycles of most guided munitions.
The focus in Russian CVLO radar has been in the 1-meter VHF band. Stealth shaping in fighters is largely ineffective in VHF because components such as stabilizers and wingtips have dimensions close to the radar wavelength. Radar-absorbent treatments developed for S-band and above are ineffective in VHF due to both electrical behavior and thickness. The flagship product is the NNIIRT/Almaz-Antey 55Zh6M Nebo M 3-D radar system, of which 100 were recently ordered to re-equip Russian air defense forces. The Nebo M is uniquely a “multi-band” design, comprising three radars and a central data fusion and command post module, all carried on separate high-mobility 8 x 8 24-ton vehicles. The Nebo-SVU was credited with space-time adaptive processing technology similar to that or the Northrop Grumman E-2D Hawkeye, and in 2002 NNIIRT's Igor Krylov said “We can see the stealth [F-117A] as clearly as any other plane”.
Advances in processing power may enable better tracking systems for long-wavelength radars that reduce the historical LO technology advantage. We know very high frequency (VHF), and ultra-high frequency (UHF) long-range air defense radars can see stealth aircraft at great distances, because LO techniques are targeted towards X-band target-tracking radar systems.28 As the longer wavelength reflects off an aircraft, it significantly increases the Radar Cross Section (RCS), which enables VHF and UHF radars to detect stealth aircraft at further distances than fire-control X-band radars.
New Russian models like the Nebo surface vehicle unit, a VHF adaptive electronically steered array radar, likely presents a significant counter-stealth capability. By 2035 other technology advances could leverage this capability.
Another counter-stealth technology is Passive Coherent Location (PCL).
Currently many countries are fielding PCL radar systems such as the Russian VERA-E, which is said to be the only system that can detect the B-2
РЛС «Небо-СВУ» (1Л119)
Радиолокационная станция «Небо-СВУ» (1Л119) предназначена для автоматического обнаружения, измерения координат и сопровождения широкого класса современных воздушных объектов: самолетов стратегической и тактической авиации, авиационных ракет типа «АСАЛМ», малоразмерных целей, малозаметных целей, в частности, выполненных по технологии «СТЕЛС»
Radar "Sky-SVU" (1L119)
Radar "Sky-SVU" (1L119) is designed to automatically identify, coordinate measuring and tracking a broad class of modern aircraft include aircraft strategic and tactical aircraft, aircraft missiles "ASALM" small targets, stealth targets, in particular, made by technology "Stealth"
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