Electronic Warfare Countermeasures

1
Electronic WarfareCounter-measures

• Naval Weapons Systems

2
EW Intro

• EW is a component of Command Control Warfare
  (C2W)
• C2W Military strategy which implements
  Information Warfare (IW). C2W includes
  integrated use of OPSEC, military deception,
  PSYOPS, EW, and physical destruction. (discussed
  more in C4I Lesson)

3
Increasing Importance of EW

• Increased reliance on radar and OTH targeting.
• Increased use of Communications and Tactical Data
  Systems (TDS).
• Increased speed of missiles and weapons systems
  requires high-speed detection and tracking.
• Active-homing or passive-homing long-range
  missiles give little warning.

4
Three Components of EW

• Electronic Support (ES) ESM
• Electronic Attack (EA) ECM
• Electronic Protection (EP) ECCM

5
Electronic Support (ES)

• Surveillance of EM spectrum for immediate threat
  recognition, threat avoidance, homing and
  targeting.
• Passive EW
• Electronic Intelligence (ELINT) Info derived
  from foreign non-comms EM information,
  particularly radar.
• Communications Intelligence (COMINT) Info
  derived from foreign comms.
• Advantages/limitations of passive EW.

6
ES Subdivisions

• Threat Warning and Avoidance
• Direction Finding
• Target Homing and Tracking

7
ES Rcvr Design Requirements

• Wide spectrum surveillance ( bandwidth )
• Wide dynamic range (weak to strong )
• Unwanted signal rejection( ability to tune )
• Angle-of-Arrival measurement( DF gt Triangulate )
• Signal Analysis capability
• ( band, modulation, side bands, lobes, PW,
  PRF )
• Display
• Recording System

8
Signal Collection Process

• Signal Warning
• Signal Sorting
• Signal Analysis

9
Electronic Attack (EA)

• Use of EM or directed energy to attack personnel,
  facilities, or equipment.
• Active and Passive EW

10
Non-Destructive EA

• Confusion Mask or hide real targets by
  cluttering the radar display.
• Jamming
• Noise Jamming
• Spot Jamming
• Barrage Jamming (AM signal, /- 10)
• Sweep Jamming ( FM )
• Chaff
• Infrared flares (Torch)

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Spot, Barrage, and Sweep Jamming
Sweep
Freq
Barrage
Spot
Ampl
Time
12
Spot and Barrage Jamming
Rcvr BW
Power
Spot Jamming
Amplitude Modulation
10
Barrage Jamming
Frequency
13
Effective Jamming
PW
Rcvd Signal Amp.
PRT
Ineffective Jamming
time
14
Non-Destructive EA (cont.)

• Deception Create a false image or changes the
  image on a radar display.
• Repeaters Create false echo by delaying rcvd
  radar signals rexmitting at later time.
• Transponders Create false signal by playing
  back a stored replica of the radar signal.
• Chaff
• Radar Decoys
• Blip Enhancers
• Radar Cross-Section (RCS) Modification

15
Receivers View of Jamming
Burn Through
16
Jamming Tactics
Self Screening Stand-off Stand Forward
17
Destructive EA

• Anti-Radiation Missiles
• SLAM
• HARM
• Sidewinder
• Directed Energy

18
Electronic Protection (EP)

• The protection of friendly combat capability
  against undesirable effect of friendly or enemy
  employment EW.
• Passive and Active EW.

19
EP Radar Design

• Power ( produce burn through )
• Frequency ( very f gt hard to jam)
• PRF ( raise PRF gt raise avg pwr )
• PW (raise PW gt raise avg pwr )
• Pulse Shape
• Antenna Design
• Scan Pattern ( phased array gt random search )

20
EP Factors

• Burnthrough Increase signal strength to
  overpower jammer noise
• Emission Control (EMCON)
• Operator Training

21
U.S. Shipboard EW Capabilities

• SLQ-32 Sidekick - on all combatants
• Radar warning, detection and jamming
• Uses an internal library to auto detect
  categorize
• Infrared Flares - on all combatants
• Chaff - on all combatants
• SSQ-108 Outboard - on Spruance class
• real-time, over-the-horizon passive detection,
  localization, and targeting
• SLQ-39 Chaff Buoy - on Arleigh Burke class

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U.S. Airborne EW Capabilities

• ALQ-142 - ES system on SH-60 Seahawk
• ALQ-99 - EW system on EA6B Prowler
• Mimics radar signals,jam,detect,ident,track,data
  link
• ALQ-126 - EA jamming system on F-14 F/A 18
• ALQ-165 - EA jamming system on F/A-18
• ALR-47 - ES detection system on S-3 Viking
• ALR-73 - ES detection system on E-2 Hawkeye
• Chaff - on SH-60 Seahawk

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Homework 6

• Read Chapter 8
• Principles of Underwater Sound
• Workbook Ch. 11 1,2,4,5,6,9,10,12,15,16,17
• Explain the difference between
  confusion/deception forms of non-destructive EA.
• What are the factors affecting EP radar design
  and why?