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ELINT Interception and Analysis course sampler

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The course covers methods to intercept radar and other non-communication signals and a then how to analyze the signals to determine their functions and capabilities. Practical exercises illustrate the principles involved.

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ELINT Interception and Analysis course sampler

  1. 1. http://www.ATIcourses.com/schedule.htm http://www.aticourses.com/ELINT_analysis_3.htm ATI Course Schedule: ATI's ELINT : ELINT Interception and Analysis Instructor: Dr. Patrick Ford
  2. 2. www.ATIcourses.com Boost Your Skills with On-Site Courses Tailored to Your Needs The Applied Technology Institute specializes in training programs for technical professionals. Our courses keep you current in the state-of-the-art technology that is essential to keep your company on the cutting edge in today’s highly competitive marketplace. Since 1984, ATI has earned the trust of training departments nationwide, and has presented on-site training at the major Navy, Air Force and NASA centers, and for a large number of contractors. Our training increases effectiveness and productivity. Learn from the proven best. For a Free On-Site Quote Visit Us At: http://www.ATIcourses.com/free_onsite_quote.asp For Our Current Public Course Schedule Go To: http://www.ATIcourses.com/schedule.htm 349 Berkshire Drive Riva, Maryland 21140 Telephone 1-888-501-2100 / (410) 965-8805 Fax (410) 956-5785 Email: ATI@ATIcourses.com
  3. 3. Copyright  1996-­‐2015   Erevno  Aerospace   •  The higher the radiated frequency... –  the smaller/lighter the required antenna/system –  the less peak power that can reasonably be radiated by the radar system –  the more the radiated energy takes on the propagation properties of light •  The lower the radiated frequency... –  the larger/heavier the required antenna/system –  the more peak power that can reasonably be radiated by the radar system –  the less the radiated energy takes on the propagation properties of light Radio Frequency Some basic rules…
  4. 4. Copyright  1996-­‐2015   Erevno  Aerospace   •  A 0 - 250 •  B 250 - 500 •  C 500 - 1,000 •  D 1,000 - 2,000 •  E 2,000 - 3,000 •  F 3,000 - 4,000 •  G 4,000 - 6,000 •  H 6,000 - 8,000 •  I 8,000 - 10,000 •  J 10,000 - 20,000 •  K 20,000 - 40,000 •  L 40,000 - 60,000 •  M 60,000 - 100,000 •  VHF 50 - 300 •  UHF 300 - 1,000 •  L 1,000 - 2,000 •  S 2,000 - 4,000 •  C 4,000 - 8,000 •  X 8,000 - 12,000 •  Ku 12,000 - 18,000 •  K 18,000 - 27,000 •  Ka 27,000 - 40,000 •  MMW 40,000 - 100,000 ElectronicWarfare RadarDesigners Frequency Band Designations (MHz)
  5. 5. Copyright  1996-­‐2015   Erevno  Aerospace   Reflection Occurs when a wave meets a plane object. The wave is reflected back without distortion. Refraction Occurs when a wave encounters a medium with a different wave speed. The direction and speed of the wave is altered. Diffraction Occurs when the wave encounters an edge. The wave has the ability to turn the corner of the edge. Scattering Catch-all description of wave interactions that are too complex to be described as reflection, refraction or diffraction. Source: www.cs.ucl.ac.uk/staff/S.Bhatti/teaching/d51/notes.html Medium 1 Medium 2 Medium 1 Medium 2 Medium 1 Medium 2
  6. 6. Copyright  1996-­‐2015   Erevno  Aerospace   Transmitter Timer Modulator Duplexer Antenna Indicator/Processor Receiver Basic Pulsed Radar System
  7. 7. Copyright  1996-­‐2015   Erevno  Aerospace   TransmitterExciter Duplexer Antenna Display Receiver Signal Processor Signal Processor High PRF results in unambiguous velocity measurements and ambiguous range measurements Doppler measurements require coherency LO and Reference Signals Pulse-Doppler Radar
  8. 8. Copyright  1996-­‐2015   Erevno  Aerospace   Pulse Repetition Interval (PRI) Pulse Repetition Frequency (PRF) Pulse Duration (PD) The Pulse Train
  9. 9. Copyright  1996-­‐2015   Erevno  Aerospace   PRF 1 PRI = PRI 1 PRF = PD = normally in usec PRF = normally in pulses per second (pps) PRI = normally in usec 1.0 second PD PRI Pulse Train PD is the length of time the illuminating power is on for each transmission PRF is the number of pulses transmitted per second PRI is the time between the start of consecutive pulses
  10. 10. Copyright  1996-­‐2015   Erevno  Aerospace   PRF(kHz) 80 Runamb(nm) = PRF • Determines radar “data rate” • Determines Maximum Unambiguous Range (MUR) - The range at which a radar can receive an echo before the next pulse is generated Source:U.S.Navy/NAWC-WDEWHandbook
  11. 11. Copyright  1996-­‐2015   Erevno  Aerospace   PD • Determines range resolution • Determines minimum range • Remember: ü PD (in feet) = 1000 feet/usec ü PD (in radar feet) = 500 feet/usec
  12. 12. Copyright  1996-­‐2015   Erevno  Aerospace   Variation of interval between pulses within the radar’s pulse train Used to eliminate MTI blind speeds, main-bang eclipsing and range ambiguities Improves anti-jamming (EP) capabilities Interpulse Modulation  
  13. 13. Copyright  1996-­‐2015   Erevno  Aerospace   Involves the process of modulating the RF carrier of a pulsed radar during transmission (within the pulse) Pulses can vary in frequency, phase or amplitude Increases range and range resolution Example: Pulse Compression Intrapulse Modulation  
  14. 14. Copyright  1996-­‐2015   Erevno  Aerospace   •  Gain: Increase/decrease in signal strength as the incoming/outgoing signal is processed by the antenna. •  Frequency Coverage: The range of frequencies over which the antenna can operate effectively. •  Bandwidth: Frequency range of the antenna in units of frequency. •  Polarization: Orientation of E and H waves. •  Beam Width: Angular coverage of the antenna in horizontal and vertical dimensions. •  Efficiency: Percentage of signal power transmitted/ received compared to a ‘perfect’ antenna. •  Power Rating: The maximum power which can be fed to the antenna without damaging the antenna and/or reducing antenna performance from the desired specifications. Antenna Performance Parameters  
  15. 15. Copyright  1996-­‐2015   Erevno  Aerospace   Antenna gain is the ratio of the power per unit of solid angle radiated in a specific direction, to the power per unit of solid angle had that power been radiated using an isotropic antenna apertureofareaeffectiveA hwavelengt mainlobeofcenteratgainantennaG 2 e e A 4G = = = = λ λ π Source: Introduction to Airborne Radar (2nd Edition) Used by permission of SciTech Publishing Antenna Gain  
  16. 16. Copyright  1996-­‐2015   Erevno  Aerospace   Polarization Note: For further information on polarization, see “Practical Communications Theory” by Dave Adamy Source: U.S. Navy / NAWC-WD EW Handbook
  17. 17. Copyright  1996-­‐2015   Erevno  Aerospace   Source:USMC/MAWTS-1 Track-While Scan Radar Beam Pattern
  18. 18. Copyright  1996-­‐2015   Erevno  Aerospace   RF  Input   (Main  Beam  -­‐  Primary  Antenna)   RF  Input   (Secondary  Omni  -­‐  antenna)   Comparator   Duplexer   Receiver   Signal     Processor   Guard  Receiver   Signal   Processor   A   B   Gate   A   Sidelobe Blanking Concept
  19. 19. Copyright  1996-­‐2015   Erevno  Aerospace   Coherent Sidelobe Cancellers (CSLC) •  Uses auxiliary receivers with antennas that have low gain and wide angle coverage –  Most CSLC radars use 3-6 auxiliary elements –  In a perfect world, one element (antenna) provides one degree of freedom and can provide one adaptive null –  The aux receivers operate on the same frequency as the primary radar receiver/ antenna •  The Howells-Applebaum method is a common CSLC implementation technique CSLC  Processor   Output   Sidelobes   Target   Return   +   -­‐  
  20. 20. Copyright  1996-­‐2015   Erevno  Aerospace   Space Time Adaptive Processing (STAP) •  STAP exploits the narrow ridge that actually forms the clutter spectrum •  STAP clutter filters have narrow clutter notches –  Slower targets fall into the receiver pass band •  Used for Doppler spread compensation caused by airborne platform motion/tactical maneuvering •  Uses a priori data to enhance the chosen STAP algorithm(s) •  Modern processing capabilities are allowing for the increased use (and development) of STAP The Principle of Space-Time Clutter Filtering (Derived from G. Richard Curry)
  21. 21. Copyright  1996-­‐2015   Erevno  Aerospace   Knowledge-Based (KB) Radar Systems •  KB radar systems can dynamically change processing when provided with data from various sources –  Processing power was the inhibiter in the past (no longer the case) •  KB-STAP now possible –  Artificial intelligence (AI) methods can be used to dynamically choose the best STAP algorithm based upon programmable factors, vice a set (single) algorithm based upon a priori data •  AI has been used to develop an expert system to dynamically modify CFAR •  Use of KB techniques to perform filtering, detection, tracking and target identification is ongoing –  NATO has held conferences on KB radar
  22. 22. Copyright  1996-­‐2015   Erevno  Aerospace   LPI Systems LPI systems can (roughly) be broken into the following technological/ operational approaches: –  Reduced ERP •  Power management based upon current situation requirements –  Reduced Sidelobes •  Low and Ultralow sidelobes –  Broadband •  Fast becoming common place for COTS marine and battlefield surveillance radar systems –  Low peak power capabilities »  Some < 1 Watt •  Natural fall-out of waveform diversity Image  sources:  Lowrance  /Kelvin  Hughes  /Thales  Group  
  23. 23. Copyright  1996-­‐2015   Erevno  Aerospace   •  Sensitivity –  Ability to receive weak signals and amplify them to usable level. It is the minimum signal strength that a receiver can receive and still operate effectively. –  Three components of sensitivity are thermal noise, receiver system noise figure, and signal-to-noise (S/N) ratio. •  Selectivity –  Ability of a receiver to tune to a particular station without other signals/ emissions interfering with the reception of the desired signal. •  Dynamic Range –  Range of signal levels over which the receiver can successfully operate. –  The low end of the dynamic range is governed by receiver sensitivity. –  The high end it is governed by the receiver’s ability to handle overload and/or strong signals. •  Frequency Stability –  Ability to stay tuned to an incoming signal for a long period of time. 22 Receiver Characteristics
  24. 24. Copyright  1996-­‐2015   Erevno  Aerospace   Low Sensitivity Crystal Video Receiver High Sensitivity Crystal Video Receiver RF  Pre-­‐amplifier   Crystal   Detector   Video  Amplifier  Antenna   Antenna   Bandpass  Filter   Crystal   Detector   Video  Amplifier  
  25. 25. Copyright  1996-­‐2015   Erevno  Aerospace   PR = PT + GT – L + GR 24 The One-way Link Equation
  26. 26. Copyright  1996-­‐2015   Erevno  Aerospace   25 Source: U.S. Navy / NAWC-WD EW Handbook
  27. 27. Copyright  1996-­‐2015   Erevno  Aerospace   26 Source: U.S. Navy / NAWC-WD EW Handbook
  28. 28. Copyright  1996-­‐2015   Erevno  Aerospace   27 Source: U.S. Navy / NAWC-WD EW Handbook
  29. 29. Copyright  1996-­‐2015   Erevno  Aerospace   Search Dimensions and Impact on POI Source:  EW  101  (Dave  Adamy)  
  30. 30. Copyright  1996-­‐2015   Erevno  Aerospace   Simplest Method of Locating Emitters: Triangulation
  31. 31. To learn more please attend this ATI course Please post your comments and questions to our blog: http://www.aticourses.com/blog/index.php Sign-up for ATI's monthly Course Schedule Updates: http://app.streamsend.com/public/fIbq/cr5/subscribe

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