The document provides an agenda for a seminar on electronic warfare for the Republic of Singapore Air Force. The seminar will cover topics such as the history of electronic warfare, definitions and terms, electromagnetic spectrum and electronic countermeasures. It will discuss concepts such as radar and communication fundamentals, vulnerabilities, jamming techniques and denial and deception. The speaker, Dr. Lee Kar Heng from the TBSS Center for Electrical and Electronics Engineering, will lead the seminar.

1. ELECTRONIC WARFARE
for the
REPUBLIC OF SINGAPORE AIRFORCE
LEE Kar Heng, Ph.D
TBSS Center for Electrical and Electronics Engineering
A TBSS Group Company

2. Seminar Timetable
Session Topics
0800 - 0815 (15 min) History of EW
0815 - 0845 (1/2 hour) Definitions and terms
0845 - 0900 (15 min) ES, EP & EP in modern warfare (specific to air
warfare, including GBAD)
0900 - 0930 (1/2 hour) Radar and Communications Fundamentals
(Surveillance and Fire Control Radars)
0930 - 0950 (20 min) Intermission (AM Tea Break)
0950 - 1020 (1/2 hour) Radar and Communications Vulnerabilities
1020 - 1040 (20 min) Jamming Concepts
1040 - 1100 (20 min) Active vs Passive Jamming
1100 - 1130 (1/2 hour) Denial and Deception Jamming
2

3. About LEE KH
ACADEMIC
 B.Tech(Hons), NUS
 Dean’s List in 4 out of 8 Semester, B.Tech(Hons), NUS
 Asia Compaq Book Prize, Top student in Year 1998, B.Tech(Hons),
NUS
 M.Eng Electrical NUS
 M.Sc Sheffied (UK)
 Certified Teacher in Higher Education, SEDA (UK) and TP
 Ph.D Engineering Management MHU (US)
3

4. About LEE KH
4
Chief, TBSS Group, TBSS Center for Electrical and Electronics Engineering, TBSS-Truong Thuong
Vietnam Trading Services, TBSS-Scilab Singapore Center, TBSS-Smiling Star, TBSS Khai Kinh Co. Ltd., TBSS
Personalized Tour Co. Ltd.
Manager, Police Technology Department, Singapore Police Force/Ministry of
Home Affairs
Section Head/Electronics Engineer, Maritime Electronics Section, Maritime and
Port Authority of Singapore
Project Manager/Consultant, Sensor Systems Division, Defence Science &
Technology Agency
Subject Head/Lecturer, School of Engineering (Telecommuications), Temasek
Polytechnic
Engineer/Member of Technical Staff, Center for Radar Systems, DSO National
Laboratories
Lecturer/Class Form Teacher, ITE Yishun/ITE Bukit Merah, Institute of Technical
Education
Field Service Engineer/Manager, Kongsberg Norcontrol, Brown Automation &
Consulting Engineering Pte. Ltd.
Electronic Specialist/Instructor, Weapon Systems (Fire Control Radar and
Computer Systems), Republic of Singapore Navy

5. About LEE KH
5
Lecturer/Subject Head, Diploma in Telecommunications, Temasek
Polytechnic (Full Time), RF Test and Measurements, Integrated Project
Lecturer, Diploma in Electronics, Temasek Polytechnic (Part Time/Full Time),
Circuits, Digital Techniques, Digital Circuits and Systems, Control Engineering
Lecturer, Specialist Diploma in Wireless Communications, Temasek
Polytechnic (Part Time), RF Techniques, Wireless Personal Communication
Lecturer/Coordinator/Developer, Basic Radar Theory and Tracking Course,
Temasek Polytechnic (Professional Short Course), Airborne Radar, 2D
Surveillance Radar, Radar Tracking Techniques and Algorithms
Lecturer, NTC-2 in Electronics Engineering, ITE (Full Time/Part Time),
Computer Technology, Electronic and Electrical Principles, Electronic and
Electrical Applications
Tutor/Project Supervisor/Course Writer, Bachelor of Science of Technology
and Bachelor of Engineering, SIM University (Part Time), Technology Project,
Info-Communication Technology, Wireless Communication Systems, Digital
Communications

6. About LEE KH
6
Lecturer/Developer, Diploma in Electronics Engineering, AIT TAFE Center
(Part Time), Electrical Principles, Amplifiers, Mathematics
Lecturer, Bachelor of Engineering/IT, University of Southern Queensland,
Informatics (Part Time), Linear Systems and Control, Algebra and Calculus II,
Discrete Mathematics, Fields and Waves, Communication Systems,
Computer Systems and Communications Protocol, Engineering Problem
Solving 3
Lecturer/Tutor/Project Supervisor, Bachelor of Engineering, Northumbria
University, Informatics (Part Time), Data Communications, Electronic Circuit
Design and Manufacture, Digital Signal Processing, Engineering Project
Lecturer, Bachelor of Engineering, RMIT University, IMC Technology (Part
Time), Radio Communication Systems Design
Lecturer/Tutor/Project Supervisor, Bachelor of Engineering, The University
of Newcastle, PSB Academy (Part Time), Introduction to
Telecommunications, Digital Communications, Final Year Project, Signals
and Systems

7. About LEE KH
7
Adjunct Senior Lecturer, Bachelor of Engineering, Edith Cowen University,
SMa Institute of Higher Learning (Part Time), Communication Systems 1,
Propagation and Antennas, Wireless Communications, Control Systems,
Engineering Practicum, Project Development
Lecturer/Course Developer, Customized WiMAX Course, Rhode and
Schwarz, Singapore, WiMAX Architecture and Standards, Physical Layers and
MAC Layer, Security and WiMAX Network Design
Lecturer/Course Developer, Basic Radar Theory and Tracking Course,
Ministry of Defence, Airborne Radar, 2D Surveillance Radar, Radar Tracking
Techniques and Algorithms
Lecturer/Course Developer, Basic Radar System Engineering, Ministry of
Defence, Introduction to Radar, Radar Plot Extraction and Tracking, Radar
Tracking Algorithms
Lecturer/Course Developer, Basic Phased Array Radar Systems, Ministry of
Defence, Introduction to Antennas, Phased Array Antenna, Beam Forming,
Adaptive Processing
C SEE

8. About LEE KH
8
Senior Adjunct Lecturer, Bachelor of Engineering, Edith Cowen
University, Responsible for the B.Eng Program in Singapore
Course Chair, Bachelor of Engineering, SIM University, Wireless
Communication Systems
Program Leader, Bachelor of Engineering, Northumbria University,
Responsible for the operations of B.Eng Program in Singapore
Member, The Institute of Electrical and Electronics Engineers (IEEE), 1995
– Present
Secretary, Education Chapter, IEEE Singapore Section, 2006 – 2007
Chairman, Education Chapter, IEEE Singapore Section, 2008 – 2009
Vice Chairman, Education Chapter, IEEE Singapore Section, 2010 – 2011
Treasure, Education Chapter, IEEE Singapore Section, 2015 – Present

9. About LEE KH
 K. H. Lee and M. S. Leong, “A Study on Coupling Effect Between Antennas Installed on a
Common Structure”, IEEE Asia Pacific Microwave Conference, 1999.
 K. H. Lee, “Antenna Coupling”, B.Tech(Hons) Project Report, NUS, 1999.
 K. H. Lee, S. A. Hamilton and M. S. Leong, “A Tri-Band Circular Polarized Microstrip
Antenna”, IEEE APS/URSI Intl. Conf., 2002.
 K. H. Lee, “A Simulation of Tracking Algorithms Used in Radar Data Processing”, M.Sc
Dissertation, University of Sheffield, 2001.
 K. H. Lee, “Design and Development of Broadband and Multiband Antennas”, M.Eng
Research Thesis, NUS, 2003.
 J. W. Teo and K. H. Lee, “The Propagation Properties Of Electromagnetic Waves In The
Application Of Through-Wall Radar Sensors”, NUS Science Research Congress, 2003.
 X. Q. Tan and K. H. Lee, “A Study on Data Fusion Techniques Used in Multiple Radar
Tracking”, NUS Science Research Congress, 2004.
 B. Moh and K. H. Lee, “A Study on the use of Frequency Modulated Continuous Wave
Radar in the Detection of Swimmers”, NUS Science Research Congress, 2005.
9

10. About LEE KH
• Mobile/Whatsapp: +65 9191 6893
• Facebook: www.facebook.com/karheng
(Personal information - opinions, comments, food, …)
• LinkedIn: www.linkedin.com/in/karheng/en
(Business information - company, work, formal articles, …)
• Academia: https://edithcowan.academia.edu/KarHengLee
(Academic information - course notes, project reports,
presentation slides, technical papers, …)
• Slideshare: http://www.slideshare.net/karheng1
(Company Information – company write up, business articles, …)
• URL: www.tbsskhaikinh.vn, www.tbss.com.sg
(Websites – contacts, address, business description, …)
10

11. EW Definitions and Terms
Technical terms are widely used in EW books and
articles, it is important to understand their
definitions correctly to fully understand the content.

12. “EW is an important capability that can advance
desired military diplomatic, and economic objectives
or, conversely, impeded undesirable ones.”
In military application, EW provides the means to
counter, in all battle phases, hostile actions that
involve the electromagnetic (EM) spectrum – from the
beginning when the enemy forces are mobilized for an
attack, through to the final engagement.”
A E Spezio, Electronic Warfare Systems, IEEE Transactions n Microwave
Theory and Techniques, Vol. 50, No. 3, March 2002, p.633
Definition of EW
12

13. • EW is not strictly
electronic
• EW is not carried out
using electrons but
electromagnetic
• Finding, exploiting
and disrupting the
enemy's
communications
• Provides an element
of force protection
Definition of EW
ELECTRONIC
WARFARE
(EW)
ELECTRONIC
COUNTERMEASURES
(ECM)
ELECTRONIC
SUPPORT
MEASURES
(ESM)
ELECTRONIC
COUNTER-
COUNTERMEASURES
(ECCM)
13
EW Divisions
(Old, but they are still being referred to)

14. Definitions and Terms
• Electromagnetic Spectrum
– Range of frequencies or wavelength of electric and
magnetic fields radiation
14
Typical
Radar
Frequencies
EW covers a
broader range of
frequencies, as
long as there is
wireless
transmission,
there is a
possible EW
activity

15. Definitions and Terms
• Electronic Support Measure (ESM)
– Actions taken to search for, intercept, locate, record
and analyses radiation EM energy, for the purpose of
exploiting such radiation to support military
operations
– Replaced by the term Electronic Warfare Support (ES)
• Electronic Counter Measure (ECM)
– Actions taken to prevent or reduce the enemy’s
effective use of the EM spectrum by attacking
personnel, facilities or equipment to degrade,
neutralize or destroy
– Replaced by the terms Electronic Attack (EA)
15

16. Definitions and Terms
• Electronic Counter-Counter Measure (ESM)
– Actions taken to ensure friendly and effective use of
the EM spectrum in the presence of enemy’s EW
– Replaced by the term Electronic Protection (EP)
• Countermeasure (ESM/EA Activity)
– Employment of devices and/or techniques to impair
the effectiveness of enemy’s operational activity
• Deception (ESM/EA Activity)
– Deliberate radiation, re-radiation, alternation,
suppression, absorption, denial, enhancement or
reflection of EM energy in a manner intended to
mislead the enemy
16

17. Definitions and Terms
• Intrusion (ESM/EA Activity)
– Intentional insertion of EM energy into transmission
paths to confuse or deceive the enemy
• Jamming (ESM/EA Activity)
– Deliberate radiation, re-radiation, alternation,
suppression, absorption, denial, enhancement or
reflection of EM energy to prevent or reduce the
enemy’s use of EM spectrum effectiveness
• Pulse(ESM/EA Activity)
– A short duration, high power surge of damaging
current and voltage (e.g. Lightning)
17

18. Definitions and Terms
• Probing (ESM/EA Activity)
– Intentional radiation of EM energy into devices or
systems to learn the function and operational
capabilities
• Reconnaissance (ESM/ES Activity)
– Detection, location, identification and evaluation of
EM radiations
• Signals Intelligence (SIGINT) (ESM/ES Activity)
– Generic terms used to describe communications
intelligence and electronic intelligence
18

19. Definitions and Terms
• Electronic Intelligence (ELINT) (ESM/ES Activity)
– Technical and geolocation intelligence derived from
noncommunications (e.g. Radar) radiations but NOT from
nuclear detonations or radioactive sources
• Communications Intelligence (COMINT) (ESM/ES
Activity)
– Technical materials and intelligence derived from EM
communications and communications systems (e.g.
Morse, voice, wireless, mobile, …)
• Security (ESM/ES Activity)
– Protection resulting from all measures to deny
unauthorized persons information from interception and
study of noncommunications EM radiation
19

20. Definitions and Terms
• Direction Finding (DF) (ESM/ES Activity)
– Equipment to provide location information of target
communication emitters
• Hardening (ECCM/EP Activity)
– Action taken to protect personnel, facilities, and/or
equipment by filtering, attenuating, grounding, bonding,
and/or shielding against undesirable effects of EM energy
• Interference (ECCM/EP Activity)
– EM disturbance that interrupts, obstructs, degrades or
limits the effective performance of electronics and
electrical equipment induced intentionally (some forms
of electronic warfare) or unintentionally (spurious
emissions and responses, intermodulation products, ..)
20

21. Definitions and Terms
• Masking (ECCM/EP Activity)
– Controlled radiation of EM energy on friendly
frequencies to protect the emissions of friendly
communications and electronic systems against
enemy ES/SIGINT, without significantly degrading the
operation of friendly systems
• EW Reprogramming (ECCM/EP Activity)
– Deliberate alteration, modification of EW or target
sensing systems or the tactics and procedures that
employ them, in response to validated changes in
equipment, tactics, or the EM environment
21

22. Definitions and Terms
• Emission Control (EMCON) (ECCM/EP Activity)
– selective and controlled use of EM, acoustic, or other
emitters to optimize command and control (C2)
capabilities while minimizing transmissions for
operations security: a. detection by enemy sensors; b.
mutual interference among friendly systems; and/or c.
enemy interference with the ability to execute a military
deception plan
• Spectrum Management (ECCM/EP Activity)
– planning, coordinating, and managing joint use of the
EM spectrum through operational, engineering, and
administrative procedures to enable electronic systems
to perform their functions in the intended environment
without causing or suffering unacceptable interference
22

23. Definitions and Terms
• Electromagnetic Compatibility(EMC) (ECCM/EP
Activity)
– ability of systems, equipment, and devices that utilize
the EM spectrum to operate in their intended
operational environments without suffering
unacceptable degradation or causing unintentional
degradation because of electromagnetic radiation or
response
23

24. Definitions and Terms
• Denial
– Control of information an enemy receives via the EM
spectrum and preventing the acquisition of accurate
information about friendly forces
24

25. Joint Electronic Type Designation System
• Military numbering system
• Prefix AN/ (it used to mean Army-Navy system)
• Followed by a 3-letter code which tells where
the equipment is used
• Followed by a hyphen (-) and then a number
• The number indicates the sequence of the
equipment, a larger number means more
modern development
AN/XXX-99 or XXX-99
25

26. Second Letter (Equipment Type)
• A - Invisible Light, Heat Radiation (e.g.
infrared)
• B - Comsec (NSA use only) (was Pigeon)
• C - Carrier (electronic wave or signal)
• D - Radiac (Radioactivity Detection,
Identification, and Computation)
• E - Laser (was NUPAC, Nuclear Protection
& Control)
• F - Fiber Optics (was Photographic)
• G - Telegraph or Teletype
• I - Interphone and Public Address
• J - Electromechanical or inertial wire
covered
• K - Telemetering
• L - Countermeasures
• M - Meteorological
• N - Sound in Air
• P - Radar
• Q - Sonar and Underwater Sound
• R - Radio
• S - Special or Combination
• T - Telephone (Wire)
• V - Visual, Visible Light
• W - Armament (not otherwise covered)
• X - Fax or Television
• Y - Data Processing
• Z - Communications (NSA use only)
Joint Electronic Type Designation System
First letter (Installation)
• A - Piloted Aircraft
• B - Underwater Mobile (submarine)
• C - Cryptographic Equipment (NSA
use only) (was Air Transportable)
• D - Pilotless Carrier (drone, UAV)
• F - Fixed Ground
• G - General Ground Use
• K - Amphibious
• M - Ground Mobile
• P - Human Portable
• S - Water (surface ship)
• T - Transportable (ground)
• U - General Utility (multi use)
• V - Vehicle (ground)
• W - Water Surface and Underwater
combined
• Z - Piloted/Pilotless Airborne vehicles
combined
Third Letter (Purpose)
• A - Auxiliary Assembly
• B - Bombing
• C - Communications (two way)
• D - Direction Finding, Reconnaissance
and Surveillance
• E - Ejection and/or Release
• G - Fire Control or Searchlight Directing
• H - Recording and/or Reproducing
• K - Computing
• L - no longer used. Was Searchlight
Control, now covered by "G".
• M - Maintenance or Test
• N - Navigation Aid
• P - no longer used. Was Reproducing,
now covered by "H"
• Q - Special or Combination
• R - Receiving or Passive Detecting
• S - Detecting, Range and Bearing, Search
• T - Transmitting
• W - Automatic Flight or Remote Control
• X - Identification or Recognition
• Y - Surveillance (target
detecting and tracking)
and Control (fire control
and/or air control)
• Z - Secure (NSA use only)

27. Joint Electronic Type Designation System
27
• AN/FPS-16 or
FPS-16
• F – Fixed ground
installation
• P – radar
• S – detecting, range
and bearing, search

28. Joint Electronic Type Designation System
28
• AN/ALQ-213 or ALQ-213 (EW Management
System)
• A – Piloted aircraft
• L – Countermeasure
• Q – Combination

29. Abbreviations
29
Term Meaning
AAM Air to Air Missile
AGA Air-Ground-Air
AGC Automatic Gain Control
ARM Anti-Radiation Missile
AAA Anti-Aircraft Artillery
ASM Air-to-Surface Missile
AOR Area of Responsibility
APOD Air Point of Departure
Backhaul Battle area extends beyond
physical bounds (the battlefield)
BSM Battle Space Management
Burn-
Through
Overcoming jamming by the
robustness of target link
CEW Communications EW
CIWS Close in Weapon Systems
CME Combat Net Radio
Term Meaning
CW Continuous Wave
Diplexer Passive device that combine
radio signals into a single
antenna
DEM Digital Elevation Model
DF Direction Finder/Finding
DME Distance Measuring Equipment
Downlink Down from air/base station to
earth/ground station
DRDF Digital Resolved DF
DTM Digital Terrain Model
DVOR Digital VHF Omni-Directional
Radio Ranging
EIRP Effective Isotropic Radiation
Pattern
ERP Effective Radiation Pattern

30. Abbreviations
30
Term Meaning
EMP EM Pulse, a damaging RF energy
for a nuclear weapon or EMP
weapon
FAA Federal Aviation Authority
FEBA Forward Edge Battle Area
FFZ First Fresnel Zone
FH Frequency Hopping
GCI Ground Controlled Intercept
Hardkill Physical destruction of assets
HUMINT Human Intelligence, informants
IFF Identification of Friend or Foe
IMINT Image Intelligence
J/S or JSR Jamming-to-Signal Ratio
LIDAR Light Detection and Ranging
MASINT Measurement and Signature
Intelligence
SSM Surface to Surface Missile
Term Meaning
MGRS Military Grid Reference System
OP Observation Post
OTHT Over the Horizon Targeting
PD Probability of Detection
POD Point of Departure
POI Point of Interception
POJ Point of Jamming
PRF Pulse Repetitive Frequency
PRI Pulse Repetitive Interval
PSO Probability of Success Operation
SAM Surface to Air Missile
SAR Synthetic Aperture Radar
SHORAD Short Range Radar
SINAD Signal in Noise and Distortion
Spoofing A radiation system pretending to
be a different system

31. Abbreviations
31
Term Meaning
SSM Surface to Surface Missile
FAA Federal Aviation Authority
FEBA Forward Edge Battle Area
FFZ First Fresnel Zone
FH Frequency Hopping
GCI Ground Controlled Intercept
Hardkill Physical destruction of assets
HUMINT Human Intelligence, informants
IFF Identification of Friend or Foe
IMINT Image Intelligence
J/S or JSR Jamming-to-Signal Ratio
LIDAR Light Detection and Ranging
MASINT Measurement and Signature
Intelligence
Term Meaning
MGRS Military Grid Reference System
OP Observation Post
OTHT Over the Horizon Targeting
PD Probability of Detection
POD Point of Departure
POI Point of Interception
POJ Point of Jamming
PRF Pulse Repetitive Frequency
PRI Pulse Repetitive Interval
PSO Probability of Success Operation
SAM Surface to Air Missile
SAR Synthetic Aperture Radar
SHORAD Short Range Radar
SINAD Signal in Noise and Distortion
Spoofing A radiation system pretending to
be a different system

32. History of EW
EW is not new , it has been practiced in major
conflicts since early 90s.
It is crucial to look at the historical development of
EW to appreciate the strategic role it plays.

33. • More than 100 years
• Started when 1st radio appeared on the
battlefield
• Radio communication changed the information
flow of military forces
• In 1901, the 1st recorded deliberate radio
jamming took place for commercial gain
• It was about the use of more powerful
transmitter to jam competitors in the reporting of
a boat race
• 1st reported use of military EW – the 1905 Russo-
Japanese War, Russian navy attempted to jam
Japanese vessels radio transmission but failed
Historical Development
33

34. • In 1914, Germans intercepted the
communication system of the British forces in
WW1
• In early 1930s, RADAR was initially developed
• During WW1, electronic deception such as
false transmissions, electronic espionage,
dummy traffic, … were deployed
• In 1939, Germans successfully located British
early warning radars
• DF was a great success in maritime operations
during WW1
Historical Development
34

35. Historical Development
35
Year Events Relating to EW through WW1
1837 S F B Morse invented telegraph
1858 US and Britain established a trans-Atlantic undersea
cable for communication
1861 Telegraph was an important target for enemy cavalry
during the US Civil War
1870 J C Maxwell establish the EM waves propagation in free
space
1888 H Hertz demonstrated electrical sparks propagation
signals into space
1895 Capt H Jackson transmitted Morse signal in England
1897 G Marconi transmitted and received signal wirelessly
over 2 km

36. Historical Development
36
Year Events Relating to EW through WW1
1899 Marconi radio sets were picking signals from 140 km
1901 1
st
recorded radio jamming in US
1902 1
st
intentional radio jamming for military purpose took
place in the Mediterranean
1905 Radio jamming was used in the Russo-Japanese War
1906 US Navy installed a DF
1914 Wide use of radio jamming, chain of DF stations were
installed by the Royal Navy
1917 US Navy installed ship borne wireless DF for anti-
submarine warfare

37. • During WW2, British equipped their aircraft
with noise jammers and passive ECM as
countermeasure
• WW2 was a competition between ECM and
ECCM
• As an example, the Chain Home Radar (early
warning radar) was built by the British to fight
against the Germans
• IFF capability was later built into British
aircrafts where Chain Home Radar was able to
identify them as a friendly target
Historical Development
37

38. • In the Japanese attack on the Pearl Harbor,
the Japanese fleet sailed across the Pacific in
total radio silence and the Simulative
Electronic Deception (SED) denied the US the
true location, intention and activities of the
fleet
• After WW2, EW development became more
aggressive and sophisticated
Historical Development
38

39. Historical Development
39
Significant Developments Leading to RADAR
Improved equipment performance and reliability
Transmission and reception of higher frequencies
Radio systems became smaller and lighter
Radio systems became available for short-range
communications
Better understanding of EM spectrum

40. • During the Korean War, B-29 were not allowed to
deploy chaff except spot jamming of fire control
radars due to potential disclosure of capability to the
Soviet
• Some B-29s were lost to the North Korea
• During Vietnam War in 1965, radar-guided surface-
to-air missiles (SAM) and radar-mounted anti-aircraft
artillery (AAA) were deployed to gun down the US
fighters
• US realized the importance of EW capability and
strengthened the EW programs
Historical Development
40

41. • In 1971, the Vietnamese deployed heaviest barrages
of AAA and SAM against the EW-equipped US aircraft
during the Hanoi and Haiphong attacks
• The 1973 Middle East War saw most of the SAM and
AAA systems in action where EM spectrum was
made full use of in target tracking and guidance
• The war pushed EW into forefront of modern
military thinking, efficient Signal Intelligence
(SIGINT) was necessary even during peace time
• If one fails to control the EM spectrum and to
gather intelligence, one may face disaster
Historical Development
41

42. • In the 1980-1988 Iran-Iraq War, the US made use
of effective jamming in the DESERT STORM,
ENDURANCE FREEDOM and IRAQI FREEDOM
operations
• The EW-armed US aircraft successfully rendered
the enemy air defense and control and command
systems (C2S) ineffective by dominating the EM
spectrum
• The deployment of Maritime Surveillance Aircraft
to map out enemy radars and C2S played an
important role in the information dominance
battlefield
Historical Development
42

43. • In the 1982 Lebanon War, the Israeli accounted
the use of decoys and real-time warfare
supported by accurate planning of EW actions to
their success
• In the 1982 Falklands War, a British destroyer was
destroyed by a sea-skimming French-built missile,
there was no airborne early warning radar on
board
• The on board missile, meant to engage aerial
platform had failed to get to the sea-skimming
missile in time
Historical Development
43

44. • It was the coordinated use of Airborne Early
Warning and Control System (AEWCS) and ECM
against the Lebanon’s Control, Control and
Communications Systems (C3S), called the C3CM
• In the 1990s, Soviet threat diminished with
budgets reducing, EW operations to the Air Force
and Navy were given up
• Throughout the 1990s, Information Warfare (IW)
doctrine transpired and this led to the
development of Information Operation (IO)
• EW is one of the core competencies in IO
Historical Development
44

45. Historical Development
45
INFORMATION OPERATIONS CORE COMPETENCIES
Electronic Warfare
Operations Security
Military Deception
Computer Network Operations
Psychological Operations
Supporting Competencies Related Competencies
Information Assurance Public Affairs
Physical Security Civil Military Operations
Physical Attack Defense Support to Public Diplomacy
Counter-Intelligence
Combat Camera

46. ES, EP and EP in Modern Warfare
(specific to Air Warfare including GBAD)
What are Electronic Warfare Support and
Electronic Project and How important are they
in Ground Based Air Defense?

47. Electronic Warfare Activities
47
ELECTRONIC WARFARE (EW)
ELECTRONIC ATTACK (EA)
ELECTRONIC PROTECTION
(EP)
EW SUPPORT (ES)
Use of EM energy, directed
energy, or anti-radiation
weapons to attack personnel,
facilities, or equipment with the
intent of degrading, neutralizing,
or destroying enemy combat
capability and is a form of fires
Passive and active means taken
to protect personnel, facilities,
and equipment from any effects
of friendly or enemy
employment of EW that degrade,
neutralize, or destroy friendly
combat capability
Actions tasked by, or under direct
control of, an operational
commander to search for,
intercept, identify, and locate or
localize sources of radiated EM
energy for immediate threat
recognition, targeting, planning
in support of EW operations and
other tactical actions
• Non-destructive • Threat warning • Protect from friendly EW
 Emission Control (EMCON)
 EW Frequency De-confliction
• Destructive • Collection supporting EW
• Direction finding
• Protect from enemy EW
 Emission Control (EMCON)
 EM Hardening

48. Electronic Warfare Activities
48
• The 3 main activities are supported by various
capabilities
Capability Description
EM Compatibility
(EMC)
Ability of systems and devices to operate in the
intended EM environment without causing an
unacceptable level of degradation
EM Deception Intentional radiation, re-radiation, alteration,
denial, suppression or reflection of EM energy to
provide misleading information to the enemy
EM Hardening Activities performed to protect personnel, facilities
and systems by filtering, attenuation, bonding and
grounding against unintentional EM radiations

49. Electronic Warfare Activities
49
Capability Description
EM Intrusion Placing EM energy intentionally into EM
transmission paths to deceive and create
confusion
EM Interference Any intentional or unintentional EM-related
disturbance that interrupts, obstruct, degrades,
and limits the effectiveness of electronics and
electrical equipment
EM Jamming A deliberate radiation, re-radiation or reflection of
EM energy to reduce or prevent enemy from using
EM spectrum, thus degrading or neutralizing
combat capability

50. Electronic Warfare Activities
50
Capability Description
EM Pulse A strong pulse that produces damaging current or
voltage to disable electronics and electrical
devices
EM Masking To protect friendly radiation against hostile ES and
SIGINT activities by controlling radiation of EM
energy of friendly frequencies
EM Probing Deliberate radiation into a potential enemy’s
devices and systems so that friendly forces can
learn about the functions and capabilities of
hostile devices and systems
EM
Reconnaissance
Detection, location, identification, and evaluation
of EM radiation

51. Electronic Warfare Activities
51
Capability Description
EM Intelligence
(ELINT)
Geological and technical Information gained from
foreign non-communications EM radiation
EM Security Activities designed to deny unauthorized persons
access to important information from interception
or non-communication radiations
EM
Reprogramming
Purposefully made changes of EM and target
sensitive systems to adopt the changes in
equipment, tactics and EM environment due to
friendly or hostile activities, so as to sustain the
effectiveness of EW and target sensitive systems
Emission Control
(EMCON)
Selective and controlled use of EM, acoustic and
other emitters to limit detection by enemy

52. Electronic Warfare Activities
52
Capability Description
Spectrum
Management
Planning, coordinating and managing the EM
spectrum so that friendly electronic systems can
perform their functions without interference or
confusion

53. Electronic Attack (EA)
• Targets facilities, equipment and personnel so as
to destroy, neutralize or degrade
• Used to be known as Electronic Countermeasure
(ECM)
• Non-destructive (soft kill) – jamming, spoofing
• Destructive (hard kill) – anti-radiation missiles
(ARM), directed energy weapons (DEW)
• EA examples are chaff, noise jamming, false
targets, angle deception and decoys
53

54. Electronic Attack (EA)
54
ELECTRONIC ATTACK (EA) TECHNIQUES
ACTIVE PASSIVE
Noise
Jamming
Deceptive
Jamming
Chemical Mechanical
Spot Range Smoke Chaff
Barrage Velocity Aerosols IR Flares
Sweep Azimuth Decoys

55. Electronic Attack (EA)
• Noise jamming – increases of background noise to
make target returns undetectable
• Spot jamming – narrowband jamming ideally
identical to the radar
• Barrage jamming – power output is spread over
bandwidth wider than the radar signal (amplitude)
• Sweep jamming – power output is swept over a
wide bandwidth (frequency)
• Deception jamming – masking the real signal by
injecting replicas to general false signals
55

56. Electronic Attack (EA)
• Range deception – breaks the missile-guiding radar
locking by capturing the radar range gate with a false echo
and moving it off to a false range
• Velocity deception – the Doppler shift is interfered by the
jammer which produces a false Doppler shifted signal to
the radar
• Angle deception – introduces angle-tracking errors in the
enemy’s fire control radar or radar-guided missile such
that the firing is missed, cross-eye and terrain bounce
jamming are angle deception techniques
• False target – creates false target returns to confuse
operators so as unable to identify real target return by use
of transponders or repeaters
56

57. Electronic Attack (EA)
• Chemical jamming – smoke or aerosol are used
against laser threat
• Chaff – composed of strips of metal foil, metal
coated dielectric fibers, thousands of which are
stored in a small space
• Flare – pyrotechnic target launched to confuse
infrared homing missiles to be decoyed away
• Radar decoys – confuses enemy and draws radar or
seeker of a radar-guided missile away from the
deploying aircraft
• DEW – high energy laser (HEL), charged particle
beam (CPB), neutral particle beams (NPB), high
power microwave (HPM)
57

58. Electronic Protection (EP)
• Used to be known as Electronic Counter
Countermeasure (ECCM)
• Protect personnel, facilities and equipment from
any friendly or hostile employment of EW that
degrade, neutralize or destroy friendly combat
capability by active and passive means
• EP is resistance to jamming
• Generally, EP techniques are based on radar
transmitted energy which is governed by its pulse
shape, power, frequency, pulse duration, antenna
parameters, …
58

59. 59
Electronic Protection (EP)
ELECTRONIC PROTECTION (EP) TECHNIQUES
Used in RADAR
Spatial
(space-based)
Spectral
(frequency-
based)
Temporal
(time-based)
Netting
Ultralow sidelobe
Low Probability
of Interference
(LPI)
Pulse
Compression
Sensor Fusion
Sidelobe
cancellation
Frequency Agility
(FA)
PRF Agility Radar Network
Sidelobe blanking Doppler Filtering Dickie Fix
Monopulse CFAR
Burn-Through

60. Electronic Protection (EP)
• Ultralow sidelobe – antenna with very low
sidelobe radiation pattern, it prevents jamming
from various angles and ARM becomes tougher
• Sidelobe blanking (SLB) – an auxiliary wide angle
antenna is used to receive target return from the
sidelobe, if there is, the return will be blanked
• Sidelobe cancellation (SLC) – use in surveillance
or tracking radar to prevent unwanted noise
jamming energies from the antenna sidelobe by
matching and cancelling processes
60

61. Electronic Protection (EP)
• Monopulse – radar illuminates target in both
azimuth and elevation in a single pulse, the
modulation of noise and ECM transmission are
different and can be recognized
• Burn-through – radar transmits with high
effective radiated power (ERP) to illuminate
targets, so as to increase the detection range of
the targets in a jamming environment
• LPI – use of spread spectrum, phased array and
low sidelobe antenna to reduce enemy radar’s
probability of detection
61

62. Electronic Protection (EP)
• FA – change of transmission frequency within
the allowed operating band
• Doppler filtering – use in tracking Doppler radar
to detect Doppler targets to defeat velocity
deception, moving target indicator (MTI) is
usually used to discriminate slowly moving chaff
from the fast moving aircraft
• Pulse compression – transmission of long pulse
on limited bandwidth, long pulse increases
illuminated energy on targets while short pulse
gives good resolution, gives optimal signal-to-
noise ratio 62

63. Electronic Protection (EP)
• PRF Agility – Pulse Repetition Frequency (PRF) of
pulse radars is varied to remove false targets, it
eliminates blind speeds in MTI systems in search or
tracking pulse radar
• Dicke Fix – protect receiver from fast sweep
jamming, continuous wave jamming and spot-noise
jamming by using broadband IF amplifier and limiter
• CFAR – constant false alarm rate where receiver
adjust its sensitivity when the intensity of undesired
signal varies so that real target returns can be
detected
63

64. Electronic Protection (EP)
• Radar netting – involves more than 1 radar to
correlate information obtained from each radar
which applies different EW techniques,
triangulation of enemy emitter
• Sensor fusion – allows information from different
sensors to be correlation to present the real
situation
64

65. Electronic Protection (EP)
65
ELECTRONIC PROTECTION (EP) TECHNIQUES
Angular Resolution Compressive IF
Amplifier
Jamming Cancellation
Receiver
Pulse-To-Pulse
Frequency Shift
(RAINDOW)
Automatic Gain Control
(AGC) Constant False Alarm
Rate (CFAR)
Mainlobe Cancellation
Autocorrelation
Cancellation of
Extended Targets (ACET)
Matched Filtering Random-Pulse Blanker
Cross Correlation Signal
Processing
Mainlobe Cancellation Range Gating
Monopulse Tracker Range Gate Memory
Automatic Threshold
Variation (ATV)
CW Jamming Canceller Multifrequency Radar Sidelobe Blanker
Dicke Fix Moving Target Indication
(MTI)
Sidelobe Canceller
Automatic tuner
(SNIFFER)
Diplexing Sidelobe Suppression
(SLS)Frequency Agility Phased Array Radar
Automatic Video Noise
Leveling (AVNL)
Frequency Diversity Polarization Diversity Staggered PRF
Guard Band Blanker PRF Discrimination Transmitter Power
Bistatic Radar High PRF Tracking Pulse Coding and
Correlation
Variable Bandwidth
ReceiverCoded Waveform
Modulation
Instantaneous
Frequency Correlator Pulse Compression,
Stretching (CHIRP)
Variable Scan Rate
Cross-Polarization Inter-Pulse Coding Velocity Tracker
Jittered PRF Logarithmic Receiver Pulse Edge Tracking Video Correlator
Wide-Bandwidth Radar Zero-Crossing Counter

66. EW Support (ES)
• Previously called Electronic Support Measures (ESM)
• ES - actions to search for, intercept, and identify
enemy use of the EM spectrum
• It also locates and localizes intentional and
unintentional EM radiation
• Primary ES purpose is immediate threat recognition,
targeting, planning, and conducting future
operations
• EW provides information required for conducting
other EW operations, targeting and homing
66

67. 67
EW Support (ES)
ES OBJECTIVES
Detection of signals present
The electrical characteristics and directional bearing of the
signals present
Determination of signal with certain prescribed characteristics
Determination of signal that tracks location of intercept
receiver
Detection of new signal in the general signal environment
Identification of unusual signal
Identification of signal showing target motion characteristics
Identification of presences of CW, FM or SSB signals

68. EW Support (ES)
• EW data also produce signals intelligence (SIGINT),
measurement and signature intelligence (MASINT),
and battle damage assessment (BDA)
• The derived intelligence detects, locates tracks,
identifies, and describes the unique characteristics
of fixed and dynamic target sources
• Threat warning is technically derived intelligence
that detects, locates, tracks, identifies, and
describes the unique characteristics of fixed and
dynamic target
68

69. EW Support (ES)
• MASINT capabilities include radar, laser, optical,
infrared, acoustic, nuclear radiation, radio
frequency, spectro-radiometric, and seismic sensing
systems as well as gas, liquid, and solid materials
sampling and analysis
• SIGINT is a strategic oriented activity and focus on
producing intelligence of an analytic nature
• SIGINT is largely made up of Electronic Intelligence
(ELINT) and Communications Intelligence (COMINT)
69

70. EW Support (ES)
• ELINT – measures direction and time of arrival
(DOA and TOA) and radar waveform signature
parameters (frequency, pulse width, bandwidth,
PRF, …) to update the ELINT parameters limits
(EPI) and provide electronic order of battle (EOB)
• COMINT – intelligence derived from potentially
hostile communications by persons other than
intended recipients via detection, collection,
classification, identification and DF of all
communications systems, data links, satellite
communications and cellular phones
70

71. EW Support (ES)
• Direction finding (DF) – to obtain bearings of radio
frequency emitters by using a highly directional
antenna and a display unit on an intercept receiver
or ancillary equipment
• Laser warning receiver (LWR) – to detect laser
signal, threat warning and collection system
• Radar warning receiver (RWR) – intercepts radar
signals and analyses the threat in real-time, by using
threat library of enemy’s EOB
71

72. Ground-Based Air Defense
• GBAD systems
– Includes air defense capabilities such as radar,
electronic warfare, weapons
– Provide deterrent and protection against threats of
attack from the air
• Aircraft threats – air-to-air and air-to-surface
weapons such as land attack missile, UAV and
long range attacks
• Rocket, Artillery and Mortar (RAM) threats –
becoming smaller, more mobile and lower cost
72

73. Ground-Based Air Defense
• Stand-Off threats – Tactical ballistic missiles (TBM)
and cruise missiles (CM) are difficult to intercept
and they are becoming more easily acquired
• Countermeasures – sensors, shooters and C2
• Raytheon MIM-104 Patriot
– Medium to Long Range Capabilities
– MPQ-53 uses phased array with IFF interrogator and SLC
to decrease interference
– Narrow antenna beam with high frequency agility and
RWR to resist jamming
– Track-Via-Missile (TVM) provides target images for the
control station to discriminate decoys
73

74. Ground-Based Air Defense
• MBDA Spada 2000
– Medium to Long Range Capabilities
– MPQ-53 radar uses phased array with IFF
interrogator and SLC to decrease interference
– Narrow antenna beam with high frequency agility
and RWR to resist jamming
• Thales Aster-30 SAMP/T
– Medium to Long Range Capabilities
– The Arabel radar is a 3D phased array radar with
beam shaping and pulse compression EP (ECCM)
74

75. Ground-Based Air Defense
• Rafael SPYDER (Surface-to-Air Python and
DERby)
– Short to medium range missile launcher
– Effective against conventional and unmanned aircraft
and threat again missile threats with low Radar Cross
Section (RCS)
– ELTA EL/M 2106 ATAR 3D Surveillance Radar: solid
state TR modules, multiple beam phased array,
digital beam forming, digital pulse compression and
digital receiver
75

76. Ground-Based Air Defense
• Rafael PYTHON
– Air-to-Air or Surface-to-Air missiles
– Short range applications
– EO/IR guided
– IRCCM
• Rafael Derby
– Short range and Beyond Visual Range (BVR) Air-to-Air
missiles
– Active radar seeker
– Fire and Forget with advanced and customizable
ECCM (EP)
76

77. Ground-Based Air Defense
• Raytheon SL AMRAAM
– Surface-launched Advanced Medium Range Air-to-Air
Missile
• Kongsberg NASAMS 2
– Network Centric Air Defense System over “hard-real-
time” communication network
– Short to medium range applications
– Works with Raytheon SL AMRAAM
– MPQ64F1 Sentinel Active 3D pencil beam radar
77

78. Ground-Based Air Defense
• Rafael Iron Dome
– Counter short-range rockets and 155 mm artillery shells up
to 70 km, day and night, under adverse weather conditions
– EL/M 2048 Detection & Tracking Radar: detects the rocket's
launch and tracks its trajectory
– Battle Management & Weapon Control (BMC): calculates
the impact point according to the reported data, and uses
this information to determine whether the target
constitutes a threat to a designated area
– Missile Firing Unit: launches the Tamir interceptor missile,
equipped with EO and several steering fins for high
maneuverability
78

79. Ground-Based Air Defense
• SAAB RBS 70 NG
– Very Short Range Air Defense (V-SHORAD)
– Automatic Target Tracking
– Integrated Thermal Imager
– Unjammable Laser Guidance
79

80. Electro-Optics and Infrared
• EO/IR are used in
– Target acquisition (detection,
recognition, identification)
– Navigation and targeting
– Laser ranging
– Intelligence, surveillance and
reconnaissance (ISR)
– EOCM, EOCCM
– IRCM, IRCCM
80

81. Electro-Optics and Infrared
• The EO in a war fighter
– Sense and collects optical frequency EM energy
– Coverts optical energy to electrical signals
– Amplifies and process the signals
– Shares the outputs with the display unit, weapon
guidance/control unit, self-protection CM/CCM device
– Recording unit
81

82. Electro-Optics and Infrared
• Some images captured using costal EO
82

83. Electro-Optics and Infrared
• In air defense, radars give detection envelope
into enemy territory and have been the most
popular sensor
• Night vision sights, laser range finder and EO are
becoming more common
83

84. EO/IR Countermeasure
• Use of EO/IR intentionally to impair the
effectiveness of enemy activity
• EO/IR is part of the EM spectrum between the
high end of the far infrared and low end of
ultraviolet
• EO/IR uses broadband jammers, smokes,
aerosols, signature suppressants, decoys,
pyrotechnics, high energy lasers, direct IR energy
84

85. EO/IR Countermeasure
85
[Video] AC-130 IR Countermeasure [Video] AH-64 Apache Helicopter Deploying
Flares Over Afghanistan

86. Radar and Communications
Fundamentals
(Surveillance and Fire Control Radars)
• What is a radar?
• What is a communication system?
• What are the differences between surveillance
and fire control functions?

87. Communication Systems
• The wired communication systems
– Wired networks
– Telephony
– Fiber communications system
– USB, HDMI, ….
87

88. Communication Systems
• The wireless and mobile communication systems
– TV and Radio Broadcasting
– Mobile phones
– Wireless networks and wireless communications
– Satellite communications
– WiFi, WiMAX, Bluetooth, …
88

89. Communication Systems
• Block diagram of a typical communication
system
89
Input
Transducer
Input message
Transmitter
Input signal
Channel
transmitted
signal
Receiver
received
signal
Distortion
and noise
Input
Transducer
Output message
output signal

90. Communication Systems
• A communication system is typical made of
– Source: originates a message such as voice, video and
text
– Input transducer: converts the message in electrical
waveform called baseband signal
– Transmitter: modifies the baseband signal for efficient
transmission over a channel
– Channel: medium such as cable, waveguide, fiber or
wireless link
– Noise: undesirable signal that affects the transmission
– Receiver: receives the noise corrupted signals and
receiver the original baseband signal
– Output transceiver: presents the received signal in an
appropriate format such as TV, microphone, computer
90

91. Communication Systems
• A must-have component in today’s defense force
• Voice communications
• In military, wireless networks are used in
vehicular applications, command posts, ad-hoc
networking, ….
• Other unattended ground sensors for
surveillance, intelligence
91

92. Communication Systems
• Spectrum – radio frequencies not limited to
specified set of values
• Spectrum management – process of regulating use
of radio frequencies
• In Singapore, the spectrum is divided in terms of
services such as aeronautical, land mobile,
meteorological and satellite services
• The unlicensed bands are free for use but users are
to comply to the regulation set
• The unlicensed band are also known as ISM band
(Instrument, Scientific and Medical)
92

93. Communication Systems
• The Singapore Spectrum Allocation Chart
93

94. Communication Systems
• The communication links in the Rafael Spyder
ADS
94
EL/M-2016
Radar Antenna
Spyder-SR
Battery

95. RADAR
• RADAR- Radio Detection and Ranging
• Theory of reflection, absorption and scattering
• Higher the frequency better the result
• Location parameters: Range, height, direction,
direction of motion, relative velocity
95

96. Applications
• Maritime, Aviation and Land navigational aids
• Height measurement (radar altimeter)
• Instrument landing (in poor visibility)
• Space applications (planetary observations)
• Radars for determining speed of moving targets
(Police radars Law enforcement and Highway safety)
• Remote sensing (weather monitoring)
• Air traffic control (ATC) and aircraft safety
• Vessel traffic safety
RADAR
96

97. Military
• Detection and ranging of targets in all weathers
• Weapon control – aiming guns at target
• Early warning on approaching aircrafts or ships
• Direct guided missiles
• Search submarines, land masses and buoys
RADAR
97

98. Ranging Concept
• Target distance is calculated from the total time
(tdelay) taken by the pulse to travel to the target
and back
• c = 3 x 108 m/s, speed of light
RADAR
98

99. Block Diagram of a Monostatic Radar
Scan Pattern
Generator
Antenna Duplexer
Waveform
Generator
Transmitter
Receiver
Signal
Processor
Data
Extractor
Data
Processor
Radar
Display
RADAR
TX RX
99

100. Radar System Components
• Antenna is highly directive with large gain
• Duplexer switches automatically
• Tx remains silent during Rx period
• Tx pulse is high power, short duration
• Rx has sensitivity to receive weak echo signals and is
be highly immune to noise
RADAR
100

101. Band Designation ITU Nominal
Frequency Range
Specific radar bands based
on ITU assignment
HF 3 – 30 MHz
VHF 30 – 300 MHz 138-144, 216-225 MHz
UHF 300 – 1000 MHz 420-450, 590-942 MHz
L 1 – 2 GHz 1215-1400 MHz
S 2 – 4 GHz 2300-2500, 2700-3700MHz
C 4 – 8 GHz 5250-5925 MHz
X 8 – 12 GHz 8500-10680 MHz
Ku 1 2– 18 GHz 13.4-14, 15.7-17.7 GHz
K 18 – 27 GHz 24.05-24.25 GHz
Ka 27 – 40 GHz 33.4-36 GHz
RADAR
101
Radar Frequency Band Designations

102. • A surveillance radar detects the presence of a target
(aircraft or ship) and determines its position and
bearing
• Usually, it observes the target over a period of time
to obtain its track
Surveillance Radar
102
2D Scanning (Range and Bearing)
Scanning
Direction
Antenna Beam
Pattern (Cosecant2)

103. Tracking Radar
• Tracking radars provide the tracks of a target
– Single Target Tracking (STT) – tracks a single target at high
data rate to provide accurate tracking of a maneuvering
target, for firing purpose
– Automatic Detection and Tracking (ADT) – tracking
performed by surveillance radar where many targets are
tracked
– Track-While-Scan (TWS) – combined searching and
tracking where a radar performs surveillance function in
normal scan and tracks all detected targets with tracking
algorithm
– Phased Array Tracking – tracking more than one track at
high update rate with electronically scanned phased
array antenna that transmits multiple beams103

104. Fire Control System
• A Fire Control System is generally made up of
– Computer – predicts the motion of the target and
extrapolates its position to some time in the future based
on assumed constant course, speed and altitude (air
target) and carries out ballistic computation to ensure
that the shell arrives at the desired point in space at a
future time
– Director – a mechanical or electronic auxiliary predictor
that computes the firing solutions for use against a
moving targets
– Radar – FCR (a STT radar) provides target information to
the computer for computation of the firing solution (so
as to direct the weapon to hit the target)
104

105. Fire Control Radar
• A STT radar that provides target information
(range, bearing, elevation or velocity) to the Fire
Control Computer
• FCR transmits narrow pencil beam pattern (gives
high directional gain) for accuracy purpose
105
Parabolic Dish Antenna
Pencil Beam Antenna Pattern

106. Fire Control Radar
• A dish antenna consists of 1
parabolic reflector and a
point source situated in the
focal point of this reflector
• This point source is called
“primary feed” or “feed”
• The parabolic reflector acts as
a mirror for the transmitted
RF energy
• Parabolic antenna gives
ideally one single reflected
ray parallel to the main axis
with minimum sidelobes
106
Reflector (Secondary Radiator)
Feed
(Primary
Radiator)
Waveguide
RF Energy from
Transmitter

107. Sequential Lobing
• A narrow beam alone is not sufficient to track a target
because as the track moves out of the beam, the FCR
will not be able to follow the move direction
• Sequential lobing – the antenna beam is switched
between 2 adjacent positions
107
Target on the
boresight
Resulting amplitudes from
the two main lobes
(The difference between
the two amplitudes is zero)

108. Sequential Lobing
• The target moves off the boresight
108
Target off
boresight
Amplitude
obtained from
main lobe A is
higher showing
that the target is
to the left of
boresight
Amplitude against Angular Error
Plot
The plot gives the angular error
from the amplitude difference

109. Conical Scanning
• In conical scanning, the offset of the main beam
is rotated around the boresight
• When the target is on the boresight, the return
signal strength remains constant throughout the
scans
109

110. Conical Scanning
• When the target moves off boresight, the return
signal strength is modulated by the position of
the target as the beam rotates
110
Amplitude varies
accordingly to the
offset position
Period/Frequency
is determined by
scan rate

111. Monopulse Tracking
• In monopulse tracking, 4 beams are transmitted
simultaneously
111
TR:
Duplexer
Target on boresight:
(A + B) – (C + D) = 0
(A + C) – (B + D) = 0
The beams will NOT
be squinted.

112. Monopulse Tracking
• The bearing error
and summation
channels in the
monopulse receiver
112
Planar Feeding
Network
Waveguide
Feeding NetworkFeeding Network

113. Anti-Aircraft Defence FCS
• [Video] Royal Danish Navy anti-aircraft defence
artillery system
113

114. Radar and Communications
Vulnerabilities
• Difference between Radar EW and
Communications EW
• Weaknesses of radars and communication
systems

115. Radar versus Communications
• EW is reactive to threats
• EW receivers are designed to detect, identify and
locate threats
• EW countermeasures are designed to reduce the
effectiveness of those threats
• Radar – measures location, distance and velocity
• Communications – carry information from one
point to another
• Radar and communications are different by
functions
115

116. Radar versus Communications
• Radar signals are pulsed or continuous wave
• Communication signals generally continuous
wave (with some pulsed wave)
• Radar signals are generally in the microwave
frequency range, but can also be as low as VHF
and into mm range
• Communication signals carry voice or data in the
HF, VHF or UHF frequency range and sometimes
in VLF to mm range
116

117. Communication Signal Threats
• Communication signals include voice
communication and digital data transmission
• Some communication signals are generally one way
but in either direction
• It is important to note that only transmitter can be
located by an emitter locator
• Communication signals are continuous and
generally have very high duty cycle compared to
radar signals
• Communications take place in the HF, VHF and UHF
ranges using amplitude, frequency and phase
modulation
117

118. Tactical Communication Threats
• Tactical communication signals – ground-to-ground,
ground-to-air and air-to-air
• In the HF, VHF and UHF
• Antennas are omni-directional such as whipped
antennas, dipoles
• Directional antennas are used between fixed sites
for high gain and isolate undesired signals
• Tactical communications use signals that are
randomly spread in azimuth and frequency to avoid
being detected
• The signal bandwidth must be large enough to
ensure that on 5% - 10% will be occupied
118

119. Digital Data Link Threats
• Digital data links carry digital information, e.g.
UAV control station links
• Uplink antennas usually have narrow beamwidth
to provide higher gain
119

120. Digital Data Link
• The uplink is usually encrypted to protect the
control station from detection and location by
hostile emitter location systems
120

121. Common Weakness
• The need to transmit via the spectrum
• If there is no transmission there is no potential
danger
121

122. Jamming Concepts
• Define Jamming, Is interference Jamming?
• Techniques used in Radar and Communication
System Jamming

123. Jamming
• It all started with radio jamming (obvious, radios
appeared before radars)
• Jamming – to prevent intended receiver from using
the radio links free in tactical environment
• Practically – limit the use of radio spectrum so that
it becomes useless tactically to the enemy (not
always jamming the link completely)
• Radio link in communications – propagation path
from the transmitter to the receiver
• Radio link in radar – link from the target to the radar
receiver
123

124. Basic Working Principles
• Jamming power (J) must be larger than the
transmitted signal power (S) (J/S >> 1)
• The Jamming-to-Signal ratio (J/S) is usually
expressed in dB, i.e. J/S must always remain
positive in dB for effective jamming (J/SdB > 0 dB)
124
ENEMY TRANSMITTER ENEMY RECEIVER
Enemy Communications Link
ENEMY TRANSMITTER
Jammer to Enemy Link
Signal Power (S)
Jamming
Power (J)

125. Basic Working Principles
• The jammer must transmit within the bandwidth
of the enemy communications link
• Transmitted power attenuates as the RF energy
travels further from the transmitter
• If the enemy transmitter-receiver distance (de) is
much shorter than the jammer-receiver distance
(dj) then the enemy transmitted power may be
high enough to over the jamming power
• This is known as burn-through
125

126. • Burn-Through of Jamming
Signal Power (S)
Basic Working Principles
126
ENEMY TRANSMITTER ENEMY RECEIVER
de
ENEMY TRANSMITTER
Jamming
Power (J)
When de << dj,
burn-through of
jamming occurs
when S >> J

127. Noise and Interference
• Noise and Interference - unwanted signals by the
system, just like jamming signal
• Noise – atmosphere and unintended sources
• Atmosphere – celestial noise source (Sun and
other stars), atmospheric noise (gases and
hydrometeors), …
• Unintended – man-made source (machinery that
produces RF energy)
• Thermal noise – receiver internal noise
• Noise affects the radio link performance
127

128. Noise and Interference
• Interference – unwanted contributed from other
intended radio systems (very different from noise)
• Intra-network interference – caused by other
transmitters within the same network
• Inter-network interference from similar radio
network – caused by transmitter within the same
radio network (e.g. two VHF communication
networks)
• Inter-network interference from difference radio
network – caused by transmitter within the same
radio network (e.g. Bluetooth and WiFi)
128

129. Types of Communications Jammers
• Jam on Tune Jamming – Jammer transmits at same
frequency and bandwidth but with higher
transmitter power
129
frequency
power
S
B
fc
Detected enemy signal
frequency
power
J
fc
Jamming signal

130. Types of Communications Jammers
• Sweep Jamming – for target signal that changes in frequency
or multiple signals, the jamming signal frequency is varied
and the enemy signal is not jammed all of the time
130
frequency
power
S
B
fc1
Detected enemy signals
frequency
Frequency
fc1
Jamming signal
fc2
fc2

131. Types of Communications Jammers
• Barrage Jamming – A broad band of spectrum is
jammed simultaneously, the jammer transmitter is
very high power to spread over a wide bandwidth
131
Detected enemy signals
frequency
power
fc1
Jamming signal
fc2

132. Radar Jamming
• Radar jamming – intentional radiation or re-
radiation of RF signals to interfere the radar
operation by
– Saturating the display with false targets (noise
jamming)
– Gives replicates the return signals enemy receiver is
expecting but with false characteristics (deceptive
jamming)
132

133. Active versus Passive Jamming
• Discuss active and passive jamming in terms of
the differences and applications

134. Definitions
• Active jammers function by transmitting a new
signal to confuse the enemy
• Passive jammers re-radiate the radar signal after
distorting it by adding noise or shift the
frequency to distort the actual signal
134

135. A Radar Jammer
• Speed gun – one that TP use in speed detection,
it usually reads the frequency shift from the
moving target
• Jammer – determines how the gun computes
the shift and manipulate the computation to
output a signal at a frequency that will deceive
the TP
• Speed gun translates the received frequency
information into a speed estimate
135

136. A Radar Jammer
• Assume that the speed gun use a center
frequency of 1 GHz
136
The spectrum is obtained by
Fourier Transform where the
frequency components of the
signals are obtained and
displayed.
Practically, it can be measured
using a Spectrum Analyzer.

137. A Radar Jammer
• When a vehicle that is moving at 100 km/h is
detected ahead of the speed gun, a shifted
component is obtained
137
The spectrum is obtained at the
speed gun receiver. In addition
to the carrier frequency
component, the speed
component in the form of
frequency shift is also present.
Noise floor

138. A Radar Jammer
• The carrier frequency component can be filtered
off by the use of low-pass filter
138
The low-pass filter removes the
high frequency components,
leaving the frequency shift from
the target.
The speed of 100 km/h gives a
frequency shift of about 120 Hz

139. A Radar Jammer
• Effect of jammer angular position relative to the target
139
It is important to
position the jammer
so that useful
information can be
obtained in passive
jamming.
The effect shown is
known as Cosine
Effect . The
measured speed,
cosam vv 

140. A Radar Jammer
• Active noise jamming – jammer transmits white
noise of high amplitude causing the speed gun to
receive random signal
• Noise jamming can be continuous or selective
(turn on when a radar transmission is detected)
• Needs high power, broadband transmitter and
usually at close range
• Easily realized (display shows random readings
or specific pattern)
• Easy to be detected (by DF)
140

141. A Radar Jammer
• Active noise jamming spectrum – similar to noise
floor, the receiver (using matched filter) shows
random speed components
141

142. A Radar Jammer
• Active deceptive jamming – when radar
transmission is detected, a signal corresponding
to a legal speed is transmitted by the jammer
• Works well as it takes time for the enemy to
realize
• Can be countered by frequency hopping
technique
142

143. A Radar Jammer
• The jammer can transmit any frequency shift, for
instance, 55 km/h while it is traveling at 100 km/h
143

144. A Radar Jammer
• Passive jammers re-radiate the radar signal after
distorting it
• Add noise and/or frequency shift such that the true
target information is being masked off
• Passive jammers neither amplify nor generate the
signal, it only redirect the radar signal back to the
speed gun
• Large antenna is required to absorb the incident
radar beams and this makes it easy to be discovered
• The re-radiated signal must be stronger than the
original radar signal and jammer must be aligned to
the speed gun
144

145. A Radar Jammer
• The jammer shifts the frequency of the incoming radar
signal slightly, the speed gun receives 3 peaks – carrier,
actual and shifted frequency components
• At the receiver output, a speed of about 60 km/h will be
displayed
145

146. Denial and Deception
Jamming
• Define denial and deception jamming
• Understand the operating concepts and
deployments of denial and deception jamming

147. Denial Jamming
• Denial jamming – to overload the enemy’s receiver so that
it becomes useless
• Transmits a noise signal powerful enough to mask the
signal the enemy’s receiver intended to receive (denial
jammer – noise jammer)
147
t
PRT (PRF)
Effective jamming – noise floor is
raised so that SNR is reduced greatly
time
Power
Signal
amplitude
ineffective
jamming
time
Power
Signal
amplitude
No jamming

148. Denial Jamming
• Active denial jamming – CW, short pulse, long
pulse, spot noise, barrage noise, sidelobe
repeater
• Passive denial jamming – chaff and radar
absorbing material (RAM)
• Denial chaff – deployed to screen targets
residing or near the deployed chaff clouds
148

149. Denial Jamming
• Denial jamming has an
advantage over the enemy
radar as the jamming signal
travels only in one direction
(half the atmospheric loss)
• Denial jammers are much more
simple to construct than
deceptive jammers
149
• Maximum transmitted jamming signal power is limited
• Burn-through – range at which the radar signal is equal or
greater than the jamming signal (where jamming becomes
ineffective)

150. Denial Jamming
• Tactical picture denial
– Preventing enemy from understanding the nature of
attacking force
– Introducing uncertainty to enemy on where and
what the attacking force is targeting on
– Decoying the enemy defense to the jamming
platform
• Strategic picture denial
– Jamming strategic defense systems to produce
confuse
– Decoying to change the enemy perception of the
actual threat
150

151. Denial Jamming
• In wireless communications, it is commonly
known as Denial of Service
– Jamming the transmission of the wireless signal that
will interfere with the carrier frequencies used
151
The Jammer
transmits on the
same radio
frequencies to
disrupt the
subscriber and
base station
Subscriber
station
Base station
Mobile
Switching
Center
Within the jamming
region, jamming
and mobile signals
collide and the
power level will be
reduced.
SS will have no
mobile service.

152. Deception Jamming
• Deception jamming injects false information into
the enemy radar to deny critical information
such as bearing, range, velocity or combination
• Deception jammer must receive the enemy radar
signal, modify the signal and transmit the
modified radar signal back to the enemy radar
• Radar signal characteristics: PRF, pulse width,
scan radar scan rate
• The process is repetitive, deception jamming is
also called repeater jamming
152

153. Deception Jamming
• Active deception jamming – use of repeater
jammer and false target generator
• Passive deception jamming – use of chaff and
RAM
• Denial chaff – the chaff cloud is dispersed to
complicate the tracking process by luring the
enemy tracker away from the target and/or
creating multiple false targets
153

154. Deception Jamming
• Deception jammers require lower power than noise
jammers as the power requirement is defined by the
average power of the enemy radar
• The process to generate a radar signal with similar
characteristic of another radar is more complex
154
RF Signal
Receiver
Detector
Memory
Signal
Modifier
RF
Oscillator
RF
Oscillator
Enemy radar
signal
Delay Line
Modified radar signal
Stores signal
characteristics

155. Deception Jamming
• The signal characteristic of enemy radar signal
requires ELINT to collect, update and provide
changes to the jammer
• It is common to deploy deception jamming to
tracking radar (or fire control radar) so as to take
the advantage in target tracking weaknesses
using false target jamming, range deception
jamming, angle deception jamming, velocity
deception jamming or monopulse jamming
155

156. Deception Jamming
• False target jamming
– To confuse enemy by generating many false targets
– Use against acquisition, early warning and ground control
intercept radar
• Range deception jamming
– After the range gate locks on cover pulse (sent by the
jammer), the radar tracks the false target in range
• Angle deception jamming
– Explore the weaknesses in antenna pattern that gives
large sidelobe
– False target enters via sidelobe to create a bearing
error
156

157. Deception Jamming
• Velocity deception jamming
– From ELINT, the Doppler information is provided
– Jammer transmits higher power CW or pulse Doppler
signal with a spurious Doppler shift
• Monopulse deception jamming
– Monopulse tracking obtains azimuth, range and
height information on pulse-by-pulse basis
– Use of filter skirt jamming to explore the weakness in
the mismatch receiver IF filter and transmitting
frequency and requires detailed knowledge of radar
receiver (not effective)
157