Cranfield University Alumni Event and
Defence Education Conference
«Integrated Air Defence
Systems - Countering Low
Observable Airborne Threats»
JUNE 2017
World War I
Battle of Britain
Dogfight over Britain
Scramble
Battle of Britain
Radar System
Observer Corps
Battle of Britain
Air Chief Marshal
Dowding
Battle of Britain
Integrated Air Defense System
Sensors
(Inputs)Control
Effectors
Integrated Air Defence System
Kill Chain
Detection
(Sensors)
Identification
(Sensor or Procedures Based)
Reaction Selection
(Rules of Engagement)
Selection of Weapon System
Engagement
Assessment
Tracking
Weapons Release
Integrated Air Defence System
Layered StructureNetworked Operation
Tracking Required for EngagementCentralized Command and Control
Technologies affecting IADS Performance
Low Observability Aircraft - Stealth Network Centered Warfare
Low Observability Aircraft – Stealth
A-6 Intruder Stealth Signature
Low
Observability
Aircraft –
Stealth
Low Observability Aircraft – Stealth
Low Observability Aircraft – Stealth
Estimated RCS for the F-35Aircraft, front sector(-45° to +45° in azimuth, -15°to +15° in elevation): 0.01 m²(with RAM)Using the POFACETS code
Reminder:0.0015 m² is the RCS value “leaked” by USAF
Operational Aspects
Low Observability Aircraft – Stealth
Operational Aspects
“First Shot” Advantage
Low Observability Aircraft – Stealth
Operational Aspects
“First Shot” Advantage
Weapons
Effective Range
(i.e 25 Miles)
Radar Weapons Quality
Track Range
Low Observability Aircraft – Stealth
Operational Aspects
“First Shot” Advantage
Data
Link
Low Observability Aircraft – Stealth
Operational Aspects
Integrated Air Defence System - STEALTH
Kill Probability
Engagement (Air/Ground
Based)
Detection Early Warning
Tracking
Tactics
Weapons
Weapon Effectiveness
Integrated Air Defence System - STEALTH
Eliminating Stealth Advantage
• Restore Early Warning Capability
• Ensure maximum weapon guidance capability
(Both Air Based and Ground Based)
• Exploitation of spectrum
Maximization of Information Flow
Countering Stealth Technology
VHF Radars
• 1-3 meters wavelegth – High RCS
• Very large Antennas
• Big Resolution Cell (Low Accuracy)
Reflections from wings – tail
Resonance Scatter
Low Scattering from shaping
features
Low effectiveness of RAM
Low Frequency Radars
Countering Stealth TechnologyLow Frequency Radars
Countering Stealth Technology
NEBO SVU System
MEADS
Low Frequency Radars
• Bistatic
• Multistatic (MIMO)
Countering Stealth Technology
Multistatic and Passive Radars
• Passive
Countering Stealth Technology
Multistatic and Passive Radars
Passive Radar
Principles of Operation
Countering Stealth Technology
Passive Radar
Advantages & Disadvantages
Advantages
• Lack of emission
• Undetectable
• Difficult to jam
• Emplacement without restrictions – no
licensing needs for operation (crucial
in radiation crowded places)
• Anti-stealth capability
• Different frequency bands usage than
conventional systems
• Possible better S/N due to distance
• Multistatic RCS
• Low construction and operation cost (no
transmitter)
Disadvantages
• Increased complexity
• High dependence on space geometry
• Dependence on uncooperative source
• Unpredictable source signal
• Emplacement & coverage restrictions
• Source emission power
• Bandwidth
• Limited detection altitude, due to lack of
exploitable emissions in high altitudes
Countering Stealth Technology
Specular Reflection
Unknown Aspect Angle
Forward Scattering
Theoretical Operation
Antennas Emplacement
DSI
Theoretical Operation
Target Position Calculation
Theoretical Operation
Target Position Calculation
Theoretical Operation
Target Position Calculation 2α: constant distances summary
2γ: focal points distance (= γ1)
Theoretical Operation
Target Position Calculation
Theoretical Operation
Target Position Calculation
Theoretical Operation
Target Velocity Calculation
Implementation of a Passive System
• RTL2832U
RTL2832U → 10,37 €
USB data connection
LNA
Results
Testing - Measurements - EvaluationTarget distance estimation capability assessment
Capabilities of Implemented System
• Range resolution 2000-2500 m
• Velocity resolution 0.50673 mach
• Noise tolerance
• SNR = 5 ∙ 10-5 = -43.0103 dB (with velocity calculation)
• SNR = 10-6 = -60 dB (without velocity calculation)
Research Systems
• NetRad by University College London
Commercial Systems
• Silent Sentry (LM Aero) • Homeland Alerter (THALES)
• AIRBUS DEFENCE • Silent Guard – Era (Chech Republic)
AESA RADARS
Independent Elements for transmittion and reception. Lobe forming by
changing the phase of the antenna elements
Electronic Scanning
AESA RADARS
Almost iminent lobe location (especially usefull in combined modes like
Track while Scan
Increased reliability (no mechanical parts)
AESA RADARS
Main disadvantage the reduction of Antenna Gain (and the range of the radar)
while scanning off boresight
AESA RADARS
44
Off boresight
Angle
AESA RADARS
Countering Stealth TechnologyInfraRed Search & Track (IRST)
Infrared Bands
Windows
Countering Stealth TechnologyInfraRed Search & Track (IRST)
Aerodynamic heating
Countering Stealth TechnologyInfraRed Search & Track (IRST)
Wavelength (microns)
AZIMUTH ANGLE
(DEGREES OF NOSE)
180°
0°
30°
60°
90°
120°
150°
2.4 2.8 3.2 3.6 4.0 4.4 4.8 5.0
100
80
60
40
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100
80
60
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100
80
60
40
20
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100
80
60
40
20
0
100
80
60
40
20
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100
80
60
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100
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Rafale OSF: IRST, FLIR, TV, Laser.
Eurofighter PIRATE: IRST, FLIR.
Gripen Skyward: IRST
Countering Stealth TechnologyInfraRed Search & Track (IRST)
F-35 electro-optical systems
AN/AAQ-40 EOTS
AN/AAQ-37 EODAS
Countering Stealth TechnologyInfraRed Search & Track (IRST)
Su-27ULB with OLS-27
PAK-FA IRSTSU-35 IRST
Countering Stealth TechnologyInfraRed Search & Track (IRST)
Range Estimation
Detection Probability
Sensor Model (PIRATE)
Array size, optics Sensitivity Different Modes
Background Radiation
Sky Radiation clouds
Atmosphere
Absorption/scattering/
RefractionBeer’s Law
F-35 Data
Engine Emissions 3D CAD Model
E=exp(-a·R)
Simulation Results
• Excellent Performance in Drought or Clean Atmosphere
• Moderate Performance in Rain or Haze
• Detection – Tracking – Threats Warning Receiver
• Passive Sensor
• Integrated Combat System (IRST, RADAR, EWS)
Conclusions
Conclusions
Improve
Detection
• VHF Radars
• Passive Radars
• OTH Radars (?)
• ……..
Improve Engagement
• Weapon range based
• Tracking
• Sensor Fusion (IRST, Radar)
• Situation Awareness (Network Centric)
Improve Kill Probability
• Tactics
Thank you!