Questions Flashcards by Conor Maguire

Q4.5.1 - ESM 1
Which is an advantage of a cavity backed spiral antenna?

Select one:
a. They have a very narrow beam width.

b. It has a linear polarisation.
c. 4 antennae will give an instantaneous 360o coverage.
d. They have a gain of approximately 35 dB.

c. 4 antennae will give an instantaneous 360o coverage.

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Q8.7.3 - IR Expendable Decoys
An Activated Metal Decoy (AMD), such as BOL IR, is used as what kind of IR CM?

Select one:

a. Reactive
b. Pre-emptive

b. Pre-emptive

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Q8.6.2 - IR Signature Reduction

Which of the following are methods of signature reduction on an aircraft?

Select one or more:

a. Airframe Shielding
b. IR Suppression
c. Active Visible Suppression
d. Baffles

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IR Jamming - Which of the following describes when the aircraft remains within the missile FoV, but a miss distance is generated. If the jamming was subsequently switched off, the missile may be able to regain track on the target and so the jamming must be continuous until the missile has flown past the aircraft.

Select one:

a. Optical break-lock
b. Guidance Suppression
c. IR Missile Tracking

b. Guidance Suppression

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Q8.3.1.5 - RF ECM

What would be the theoretical power loss (in decibels) for a jamming signal that has a total polarisation mismatch with a radar receiver?

-26dB

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Q4.1.1.8 - Basic Radar Concepts
What is the range of a target from a pulse Radar if the pulse takes 500 us to arrive back at the receiver?

Select one:
a. 150 kM

b. 75 kM
c. 15 kM
d. 7.5 kM

b. 75 kM

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Complete the sentences…

Look‑Through OR Look‑Over

- This is a time-sharing technique where jamming is periodically interrupted to check for signal changes. This allows search-lock jammers to operate against frequency agile radars, but their effectiveness may be degraded against several frequency agile radars operating in the same frequency band. [?]*
- This technique is based on physically separating the Rx and Tx antennas of the jammer. This jamming is used where there is sufficient isolation between the jammer receiver / transmitter frequency range, or antenna coverage patterns, to allow the receiver to operate whilst the jammer is transmitting. [?]*

RF ECM On-Board Techniques

This is a time-sharing technique where jamming is periodically interrupted to check for signal changes. This allows search-lock jammers to operate against frequency agile radars, but their effectiveness may be degraded against several frequency agile radars operating in the same frequency band. [Look‑Through]
This technique is based on physically separating the Rx and Tx antennas of the jammer. This jamming is used where there is sufficient isolation between the jammer receiver / transmitter frequency range, or antenna coverage patterns, to allow the receiver to operate whilst the jammer is transmitting. [Look‑Over]

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Application of EW in Space

Match the following orbit types to their description.

LEO and MEO

[?] orbits are better for IMINT or ELINT due to their close proximity to the earth.

[?] orbits are at a higher altitude ensuring that satellites have a bigger footprint on the ground. In general most satellites in this orbit are manoeuvred into a circular orbit with a period of 12 hours. This means that they will orbit the earth twice a day (known as semi-synchronous).

[LEO] orbits are better for IMINT or ELINT due to their close proximity to the earth.

[MEO] orbits are at a higher altitude ensuring that satellites have a bigger footprint on the ground. In general most satellites in this orbit are manoeuvred into a circular orbit with a period of 12 hours. This means that they will orbit the earth twice a day (known as semi-synchronous).

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Jamming & Frequency Hopping

What was one of the first Electronic Protection Measures (EPM) to be used to counteract Communications Jamming?

Select one:

a. Transmission encryption
b. Frequency hopping

b. Frequency hopping

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ESM 2 - In order to be effective a Super Hetrodyne Receiver (SHR) system requires:

Select one:

a. Mission dependent data.
b. Manual control by the aircrew.

a. Mission dependent data.

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Synthetic Aperture Radar

How does SAR solve the azimuth along track resolution issue?

Select one:

a. Synthetically creating a very large radar aperture.
b. FM modulation

a. Synthetically creating a very large radar aperture.

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Q2.2.2.5 - Phase, Polarisation & Propagation

What are the 3 main types of polarisation?

Vertical, Horizontal and Circular

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True or False

Eclipsing is the term given to the blindness that a Radar experiences when the doppler shift imposed on a return is the same as the transmission PRF value.

False

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Use of EO - Label the missing parts of an early EO sensor.

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Q7.1.1 - LASER

Laser light is very different from normal light and has the following properties:

The light released is ? meaning it contains one specific wavelength of light (one specific colour). The wavelength of light is determined by the amount of energy released when the electron drops to a lower orbit.
The light released is ? meaning each photon moves in phase with the others. This means that all of the photons have a wave front that launches in unison.
The light is very ? giving a very tight, concentrated beam. A flashlight, on the other hand, releases light in many directions, and the light is very weak and diffuse.

Q7.1.1 - LASER

Laser light is very different from normal light and has the following properties:

The light released is monochromatic meaning it contains one specific wavelength of light (one specific colour). The wavelength of light is determined by the amount of energy released when the electron drops to a lower orbit.
The light released is coherent meaning each photon moves in phase with the others. This means that all of the photons have a wave front that launches in unison.
The light is very directional giving a very tight, concentrated beam. A flashlight, on the other hand, releases light in many directions, and the light is very weak and diffuse.

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EO Fundamentals - Which colour is scattered most by atmospheric particles?

Select one:

a. Blue
b. Orange
c. Red

Blue

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EO Fundamentals - Which 3 primary regions of the EM spectrum make up the EO spectrum?

Select one:

a. UV, IR & EO
b. IR, Visible, UV
c. Radar, IR & UV

b. IR, Visible, UV

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Airbone Radar- Is the following statement True or False?

A ground mapping scan can be used for navigation, allowing real-world radar reflections to be overlayed on a map, so an operator can confirm navigational accuracy. This is particularly useful in an environment where GPS may get jammed.

Select one:

True

False

True

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True or False

Denial and Deception

A Swept Spot Jammer jams continuously over a wide frequency range, covering the frequency band used by agile radars and thus can also jam a number of systems operating at different frequencies all at once.

False

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Synthetic Aperture Radar

Earth-resource mapping. Geologists can use SAR for terrain structural information, gathering data on mineral exploration, as well as providing details to develop sea state and ice hazard maps.

Select one:

True

False

True

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Synthetic Aperture Radar

Identify the SAR modes of operation:

Select one or more:

a. Sliding mode.
b. Scan MTI mode.

a. Sliding mode.

b. Scan MTI mode.

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Complete the sentences…

AM means [?] Modulation.

PPM means [?] Modulation.

FSK means [?] Modulation.

Further Modulation Techniques

Identify the correct Modulation techniques.

AM means [Amplitude] Modulation.

PPM means [Pulse Position] Modulation.

FSK means [Frequency Shift Keying] Modulation.

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Q9.1.5 - MOD EW Organisations

Is the following statement True or False?

92 Sqn is based at HQ ASWC and develop tactical advice and training for the front line. 92 Sqn SMEs are responsible for the production of Tac Memos for front line units, which will furnish them with tactical advice on different theatres of operation or tactics, techniques and procedures (TTPs).

True

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DEW- Match the following Directed Energy Weapons (DEW) with their real-world applications:

High Power Microwave (HPM) weapon. (One of…)

Long Range Acoustic Device (LRAD).

Active Denial System (ADS).

Personnel Halting And Stimulation Response (PHASR) rifle.

Sonic or ultrasonic weapon. (One of…)

Long Range Acoustic Device (LRAD).

Active Denial System (ADS).

Personnel Halting And Stimulation Response (PHASR) rifle.

The correct answer is:

High Power Microwave (HPM) weapon. → Active Denial System (ADS).

Sonic or ultrasonic weapon. → Long Range Acoustic Device (LRAD).

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*Complete the sentences...* The correct answer is: False targets in **?** may be generated at greater ranges than the true target by delaying and then re-transmitting replicas of the radar pulse. Transmitting jamming signals with a small frequency shift, thereby falsifying Doppler shift and creating false targets in **?.**

The correct answer is: False targets in **range** may be generated at greater ranges than the true target by delaying and then re-transmitting replicas of the radar pulse. Transmitting jamming signals with a small frequency shift, thereby falsifying Doppler shift and creating false targets in **Velocity.**

IR Manpads - Label the component parts of this MANPADs by dragging and dropping labels in the correct places.

The Missile. The kinetic vehicle intended to destroy the target; each round was really a "hit-ile", until later systems started using a proximity fuses and thus became "Miss-iles". It is mostly made up of solid rocket propellant, giving it the longest possible distance to engage a target. Some later systems augment this with an aerodynamic spike to increase the range, but earlier systems have a characteristic blunt nose. Behind the nose is the seeker head, for which the guidance process was covered in the IR Guidance lesson. These guidance signals must be interpreted by the guidance control pack just behind the seeker head, which translates this into a steering command for the control canards. The warhead is usually only a couple of kg big due to the restricted space available and weight (thus range) penalty. The rear of the round has stabilisation fins to keep the flight profile smooth. All this is shown in the diagram below, in which you can also see the eject motor - this pushes the round out of the launch tube to a safe distance before the rocket propellant fires up, saving the operator from having their face burned.

*_EM Fundamentals - Waves & Electrics_* *_Identify the following SI Units:_* Power Frequency

The correct answer is: Power (P) = → Watts (W), Frequency (f) = → Hertz (Hz)

*_Denial and Deception_* *_Select the correct subdivisions of ECM._* **Select one or more:** a. Jamming b. Neutralisation c. Deception d. Identification

**a. Jamming** **b. Neutralisation** **c. Deception**

Put the stages in order... Measure the original the radar pulse frequency Walk the pulse off in either range or velocity (RGPO or VGPO dependent) 1. **[?]** 2. Slowly build up a cover pulse to 5-6 dB stronger to capture the AGC. 3. **[?]** 4. Drop the lock and repeat the process to prevent re-acquisition.

RF ECM On-Board Techniques *_When employing an RGPO/VGPO ECM sequence, drag and drop the stages to create the correct order of events:_* 1. [**Measure the original the radar pulse frequency**] 2. Slowly build up a cover pulse to 5-6 dB stronger to capture the AGC. 3. [**Walk the pulse off in either range or velocity (RGPO or VGPO dependent)**] 4. Drop the lock and repeat the process to prevent re-acquisition.

Q4.6.2 - ESM 2 An advantage of Super Hetrodyne Receiver (SHR) over a Crystal Video Receiver (CVR) is that it is:

More accurate in frequency measurement.

*_IR Jamming - Which of the following describes where a Jammer producing sufficient J:S ratio deceives the seeker such that the aircraft is outside of the missile FoV. At this point the missile is defeated and, if the jamming were subsequently switched off, the missile would not regain track on the target._* **Select one:** a. Optical Break-lock b. Guidance Suppression c. Deception Jamming

**a. Optical Break-lock**

Q4.3.8 - Airborne Radar What modification has been made to some airborne AESA to improve the scan angle during manoeuvres? Select one: a. The graceful degradation of transmitter elements. b. A reduction in the overall scan rate. c. Bearings and motors with graphite slip rings. d. The addition of a movable swash-plate.

**d. The addition of a movable swash-plate.**

*_Data Links- Time Division Multiple Access (TDMA) breaks each day in what periods of time?_* **Select one:** a. Hours, Minutes & Seconds b. Mornings, Afternoons & Evenings c. Epochs, Frames & Time slots

**c. Epochs, Frames & Time slots**

Q8.5.5 - IR MANPADS If you think you have had a passive tracking missile fired at you (e.g. MANPADS, Rockets, RPGs etc) what are the key identifying items to report back to the Intelligence Community, via the MISREP, to allow assessment and wider awareness? Select one: a. Manoeuvre, Intensity, Smoke, Sparkle, Self-destruct b. Miss-distance, Intensity, Smoke, Scan type, Self-destruct c. Manoeuvre, Intensity, Smell, Scan type, Self-destruct d. Manoeuvre, Intensity, Smoke, Sparkle, Spin Speed

**a. Manoeuvre, Intensity, Smoke, Sparkle, Self-destruct**

*_Application of EW in Space_* *_What are the three segments that make up our Space capabilities, and thus could be targeted with EW?_* **Select one:** a. Air, Land, and Sea Segments b. Space, Ground, and Link segments

**b. Space, Ground, and Link segments**

**a. Optical Break-lock**

EM Fundamentals - Phase, Polarisation & Propagation ## Footnote **Label the different types of EM Propagation on the picture below:**

*_MWS- A MWS could detect missiles / hostile fire by sensing:_* **Select one:** a. Muzzle flash, Motor ignition, Motor plume, Kinetic heating, or the Mass/RCS and relative velocity. b. Muzzle flash, Motor noise, Motor plume, Kinetic heating, or the Mass/RCS and relative velocity. c. Muzzle flash, Motor ignition, Motor plume, Seeker Head signals, or the Mass/RCS and relative velocity.

**a. Muzzle flash, Motor ignition, Motor plume, Kinetic heating, or the Mass/RCS and relative velocity.**

*_Q7.2.3 - Laser Weapon System (LaWS). LaWs is a 0.5kW solid-state laser weapon system designed to counter the IED threat in Afghanistan by disabling mines and UXOs left on the battlefield._* **Select one:** True False

**False**

Q8.2.2 - RF Signature Reduction Air Traffic Control at Lossiemouth are having problems seeing recovering jets at 2000ft because of windfarms on a hill 20nm from the airfield. What RF signature reduction technique could be used at the windfarm to help with this? Select one: a. Radar Absorbent Paint (RAP) b. Wind turbine baffles c. Fuel additives d. Wind turbine rotor head cowlings

**a. Radar Absorbent Paint (RAP)**

* Complete the sentence...* * Bandwidth is the amount of [?] space a signal occupies, and is an important consideration when designing [?] Systems. The utilisation of [?] bandwidths costs more money and the more we use, the less is [?] for other tasks.*

Basic Modulation Techniques Bandwidth is the amount of [**frequency**] space a signal occupies, and is an important consideration when designing [**Communications**] Systems. The utilisation of [**larger**] bandwidths costs more money and the more we use, the less is [**available**] for other tasks.

*_Improved Target Detection_* **Which of the following is a form of Pulse Compression?** Select one: a. Bi-phase PSK b. Pulse Position Modulation

a. Bi-phase PSK

*_IR Manpads - The future threat from the development of MANPADS is heightened via the addition of:_* **Select one:** a. Larger warheads b. Proximity Fuses c. Multi-spectral seeker heads d. All of the above

**d. All of the above**

Pulsed Radar Fundamentals Fill in the blanks. In Secondary Radar systems, which can include IFF and AIS (Automatic Identification System), a radar sends a coded message to a [?] located on the target, which contains data to interrogate the aircraft. The target responds to the interrogation using a separate [?] operating at a different frequency.

In Secondary Radar systems, which can include IFF and AIS (Automatic Identification System), a radar sends a coded message to a [**transponder**] located on the target, which contains data to interrogate the aircraft. The target responds to the interrogation using a separate [**transmitter**] operating at a different frequency.

*_IR Signature - Name two methods of reducing acoustic signature on rotary wing aircraft._* **Select one:** a. Main-rotor blade tip shaping, rotor head cowls b. Chevron nozzles, rotor-head cowls c. Main-rotor blade tip shaping, high-bypass ratio turbofans

**a. Main-rotor blade tip shaping, rotor head cowls**

Q5.2.3 - IR Guidance With this type of guidance reticle, the target image is nutated over a fixed reticle by a wedge or a canted mirror that spins with the gyro. This means that with the missile tracking towards the target, the IR hot spot is pushed out of the area in the centre of the reticle so there is a strong target signal.

Con-Scan

*_Basic Modulation Techniques._* *_What output frequencies would be produced by mixing a 75Hz input signal with a 300kHz local oscillator signal?_* **Select one:** a. 75kHz, 225kHz, 300kHz and 375kHz b. 75Hz, 299.925kHz, 300kHz, 300.075kHz c. 75Hz, 225kHz, 300kHz and 375Hz d. 75Hz, 299.25kHz, 300kHz, 300.75kHz

**b. 75Hz, 299.925kHz, 300kHz, 300.075kHz**

Q4.6.2 - ESM 2 An advantage of Super Hetrodyne Receiver (SHR) over a Crystal Video Receiver (CVR) is that it is: Select one: a. More accurate in frequency measurement. b. Able to detect simultaneous frequencies across the entire frequency range. c. Faster in response time. d. Cheaper.

**a. More accurate in frequency measurement.**

Q5.2.5 - IR Guidance This reticle and associated scanning design allows a detector to be moved across a scene in order to process it quickly, giving a smaller IFOV but a more accurate guidance command signal.

Pseudo-Imaging

Q8.7.4 - IR Expendable Decoys Missiles which can distinguish between IR Band 1 and Band 4 outputs are said to have what kind of IRCCM?

Spectral Ratio

Data Links - A data link is the means of transmitting digital information from one terminal to another. What general data link types are used within the air environment? **Select one:** a. Local and remote b. In-board and out-board c. On-board and off-board d. Interior and exterior

**c. On-board and off-board**

Q4.5.3 - ESM 1 Consider the following statement: An ELINT platform is able to extrapolate RF data to build a picture of the battle-space. With known information, it is able to identify types of threat, as well as distinguish friendly signals from the potential threat signals.

True

*_Synthetic Aperture Radar_* ## Footnote **Label the different SAR Modes.**

Q8.3.3.5 - RF ECM On-Board Techniques RF jamming alone is not always entirely successful at preventing a radar from locking on to its target. Select the additional techniques that can be used to help jamming achieve its aim. Select one or more: a. Aircraft Manoeuvres b. Expendable Active Decoys (EAD) c. Flares d. Chaff

**a. Aircraft Manoeuvres** **b. Expendable Active Decoys (EAD)** **d. Chaff**

*_EM Fundamentals - Phase, Polarisation & Propagation_* *_Why is it impracticable to transmit signals at a Frequency of 60 GHz?_* **Select one:** a. High atmospheric attenuation levels b. Poor Antenna characteristics at this frequency

**a. High atmospheric attenuation levels**

*_Spread Spectrum & Encryption_* *_Frequency Hopping, Channel Multiplexing, Spectrum Spread and CDMA are all methods to defeat .............?_* **Select one:** a. Encryption b. Jamming

**b. Jamming**

Q3.4.6 - Data Links On which system is MIDS used?

Link-16

_*Q1.2.5 - EW Definitions Which of the following points are part of an effective summary of EW:*_ Select one or more: a. Commanders must seek to control the areas of the spectrum their forces are operating in, whilst denying / exploiting the areas in which opposing Forces are operating. b. EW aims to enhance mission effectiveness, rather than be the mission itself. c. Recent air campaigns have not demonstrated the vital role played by EW. d. A major aspect of EW is to enhance the survivability of friendly aircraft and other assets.

a. Commanders must seek to control the areas of the spectrum their forces are operating in, whilst denying / exploiting the areas in which opposing Forces are operating. b. EW aims to enhance mission effectiveness, rather than be the mission itself. d. A major aspect of EW is to enhance the survivability of friendly aircraft and other assets.

Q4.3.1 - Airborne Radar What type of scan pattern would a fast jet AI aircraft use to search a large area for airborne targets? Select one: a. conical scan b. raster scan c. ground mapping d. monopulse scan

**b. raster scan**

The deliberate radiation, re-radiation, alteration, absorption or reflection of EM energy in a manner intended to confuse, distract or seduce an adversary or his electronic systems. Electronic deception can also be used to assist with military deception. The deliberate radiation, re-radiation or reflection of EM energy, with the objective of impairing the effectiveness of electronic devices, equipment or systems being used by an adversary. The deliberate use of EM energy to either temporarily or permanently damage adversary devices that rely exclusively on the EMS, usually brought about as a result of a directed energy (DE) weapon depositing efficient EM energy on a target so as to render the target, its electronics or both, useless. That division of Electronic Warfare involving actions taken to prevent or reduce an enemy’s effective use of electromagnetic spectrum through the use of electromagnetic energy.

Deception Jamming Neutralisation ECM

IADS- Match the correct C2 element name to its function within an IADS: Holds primary control of the IADS → ? Holds operational control of a given sector → ? Compiles the RAP and provides tactical control of the airspace → ?

Holds primary control of the IADS → **CAOC** Holds operational control of a given sector → **SOC** Compiles the RAP and provides tactical control of the airspace → **CRC**

*_Use of EO- Which of the following statements regarding EO sensors is incorrect?_* **Select one:** a. EO sensors are not affected by mountainous terrain. b. Night time will limit systems using the visible band. c. Vulnerability to counter-measures depends on auto-tracker and / or operator capability.

**a. EO sensors are not affected by mountainous terrain.**

*_Application of EW in Space_* *_What are the two current GPS signal formats?_* **Select one:** a. P(Y) and C/A b. P(k) and C/A

**a. P(Y) and C/A**

*Complete the sentence...* Broad or Narrow band [?] is a method use to either absorb the radar energy, or is tuned to 1/2 the wavelength and thus cancels out the return signal. [?] contains tiny spheres of material that vibrate upon contact with RF energy, turning a high percentage into heat energy and thus less is reflected to the originating system. [?] are those items on an aircraft which could act as cavities or reflectors, meaning the RCS of an aircraft could be enhanced if not properly managed.

Broad or Narrow band [**RAM**] is a method use to either absorb the radar energy, or is tuned to 1/2 the wavelength and thus cancels out the return signal. [**RAP**] contains tiny spheres of material that vibrate upon contact with RF energy, turning a high percentage into heat energy and thus less is reflected to the originating system. [**RAS**] are those items on an aircraft which could act as cavities or reflectors, meaning the RCS of an aircraft could be enhanced if not properly managed.

Q8.8.1 - IR Jamming The aim of an IR jammer is to distort the guidance information derived by an IR missile seeker, causing the missile to miss its intended target. Airborne IR jammers can provide **?** continuous protection and are **?**. The disadvantages of active IRCM systems include significant electrical power, **? and ?**.

The aim of an IR jammer is to distort the guidance information derived by an IR missile seeker, causing the missile to miss its intended target. Airborne IR jammers can provide **pre-emptive** continuous protection and are **visually covert**. The disadvantages of active IRCM systems include significant electrical power, **drag and weight**.

Q4.2.14 - Doppler Which of the following pulse characteristics can be used used to eliminate blind speeds? Electronic Protective Measures (EPM). Select one or more: a. pulse width b. multi-PRF values c. pulse stagger d. pulse jitter

**b. multi-PRF values** **c. pulse stagger** **d. pulse jitter**

Q5.3.5 - IR MWS What are the advantages of a UV MWS? Select one or more: a. Ability to classify missile type b. Medium detection range capability c. Covert d. Relatively simple, cheap and mature

**b. Medium detection range capability** **c. Covert** **d. Relatively simple, cheap and mature**

*_RF Signature Reduction_* *_When Narrow Band RAM is used on an aircraft, what change in wavelength (λ) would effectively neutralise the returning signal?_* **Select one:** a. λ/2 b. λ

**a. λ/2**

*_Doppler- Is the following statement True or False?_* **The main use of the Doppler effect in Radar systems is to measure the velocity of moving targets and to remove clutter returns caused by stationary objects.** Select one: True False

**True**

*_Improved Target Detection_* **What is the main reason for using pulse compression?** Select one: a. More power is present within the pulse, so will travel further. b. A large pulse width provides excellent range resolution.

a. More power is present within the pulse, so will travel further.

Denial and Deception With (Swept Spot Jammers **_OR_** Barrage Jammers) the noise jamming signal can be swept across the entire range of frequencies over which the victim radar can hop, or can also be used when several radars are operating on similar frequencies. (Swept Spot Jammers **_OR_** Barrage Jammers) act continuously over a wide frequency range, covering all the frequencies used by agile radars and thus can also jam several systems operating on similar frequencies at once.

Denial and Deception With [**Swept Spot Jammers**] the noise jamming signal can be swept across the entire range of frequencies over which the victim radar can hop, or can also be used when several radars are operating on similar frequencies. [**Barrage Jammers**] act continuously over a wide frequency range, covering all the frequencies used by agile radars and thus can also jam several systems operating on similar frequencies at once.

Q2.3.1 - EO Fundamentals Which 3 primary regions of the EM spectrum make up the EO spectrum? Select one: a. UV, IR & EO b. Near IR, Mid IR & Far IR c. IR, Visible, UV d. Radar, IR & UV

**c. IR, Visible, UV**

*_Further Modulation Techniques_* *_In Quadrature Phase Shift Keying (QPSK), how many combinations of a 2-bit binary word are possible, and what is the maximum margin of error in degrees? ._* **Select one:** a. 2 combinations and +/- 45 degrees b. 4 combinations and +/- 90 degrees c. 4 combinations and +/- 45 degrees

**c. 4 combinations and +/- 45 degrees**

*Complete the sentence...* ISDS- A country that relies primarily on SAMS has a **[?]** and a country that relies on air assets to defend itself has a **[?]**.

ISDS- A country that relies primarily on SAMS has a [**Missile Defence IADS**] and a country that relies on air assets to defend itself has a [**Air Defence IADS**].

*_LASER- Which of the following describes the acronym LASER?_* **Select one:** a. Light Amplification by Stimulated Emission of Radiation. b. Local Attenuation by Substantial Emission of Radiation. c. Light Attenuation by Saturated Emission of Radar

**a. Light Amplification by Stimulated Emission of Radiation.**

*_Denial and Deception_* *_The deliberate radiation, re-radiation, alteration, absorption or reflection of EM energy in a manner intended to confuse, distract or seduce an adversary or his electronic systems is called:_* **Select one:** a. Deception b. Identification

**a. Deception**

*_RF ECM On-Board Techniques_* *_What is the ECM monitoring technique below called:_* This is a time-sharing technique where jamming is periodically interrupted to check for signal changes. This allows search-lock jammers to operate against frequency agile radars, but their effectiveness may be degraded against several frequency agile radars operating in the same frequency band.

a. Look-Through

*_Basic Target Detection_* *_What the minimum detectable target range for Radar using a pulse width of 0.4 uS and a duplexer recovery time of 0.1 uS?_* **Select one:** a. 75 m b. 150 m

**a. 75 m**

*_Improved Target Detection_* When a return echo carrying FM Pulse Compression is received, the pulse is passed into a filter which introduces a **"... ... ..."** delay (varying linearly with frequency). The filter characteristics are chosen such that the frequencies received first are **"... ... ..."** the most, thereby allowing subsequent parts of the pulse to catch up (delay line). The later higher frequencies within the return pulse are delayed for the shortest time, with the net effect being to compress the pulse back down to its original width.

When a return echo carrying FM Pulse Compression is received, the pulse is passed into a filter which introduces a **[time]** delay (varying linearly with frequency). The filter characteristics are chosen such that the frequencies received first are **[delayed]** the most, thereby allowing subsequent parts of the pulse to catch up (delay line). The later higher frequencies within the return pulse are delayed for the shortest time, with the net effect being to compress the pulse back down to its original width.

Q4.1.4.4 - Improved Target Detection Which of the following are types of Pulse Compression? **Select one or more:** a. FM Pulse Compression (Chirp). b. Quadrature Phase Shift Keying (QPSK). c. AM Pulse Compression (Squelch). d. Barker Coded Pulse Compression.

**a. FM Pulse Compression (Chirp).** **d. Barker Coded Pulse Compression.**

*Complete the sentence...* LASER - Laser light differs from normal light and has various properties: The wavelength of light is determined by the amount of energy released when the electron drops to a lower orbit. The light released is **[?]**, meaning it contains one specific wavelength of light (one specific colour). Each photon moves in phase with the others thus the light released is **[?]**.

LASER - Laser light differs from normal light and has various properties: The wavelength of light is determined by the amount of energy released when the electron drops to a lower orbit. The light released is [monochromatic], meaning it contains one specific wavelength of light (one specific colour). Each photon moves in phase with the others thus the light released is [coherent].

Q4.7.2 - Synthetic Aperture Radar How does SAR solve the azimuth along track resolution issue?

Synthetically creating a very large radar aperture.

Identify the SAR modes of operation: Select one or more: a. Squinted strip mode. b. Sliding mode. c. Scan MTI mode. d. Raster scan mode

**a. Squinted strip mode.** **c. Scan MTI mode.**

*_Pulsed Radar Fundamentals_* *_Which of the following Radar system is classed as a secondary Radar?_* **Select one:** a. IFF b. Early Warning Radar

**a. IFF**

*_IR Signature- The purpose of putting an IR-suppressant additive into jet fuel mix is to reduce the overall IR energy output and thus avoid detection._* **Select one:** True False

**False** **Suppressants do not necessarily lower the overall energy output, just move it into a different area of the EM spectrum to avoid detection from certain systems.**

*Complete the sentences...* Switching off the seeker briefly and memorising the intercept flight path = **?** Pushing the seeker in front of the target to force flares outside the FoV = **?**

The correct answer is: Switching off the seeker briefly and memorising the intercept flight path → **Blinking** Pushing the seeker in front of the target to force flares outside the FoV → **Nudge ahead**

*_IR Guidance - The latest generation of IR missiles use these type of IR seekers or multi-element detectors, whereby the 2-dimensional target scene is imaged on the detector in the seeker optical system for true ‘staring’ techniques._* **Select one:** a. Spin Scan b. Con Scan c. Focal Plane Array

**c. Focal Plane Array**

*_DEW - What is the meaning of DEW?_* **Select one:** a. Directed Energy Weapon. b. Developed Energy Weapon. c. Doppler Emission Wobble.

**a. Directed Energy Weapon.**

*_RF ECM On-Board Techniques_* *_RF jamming alone is not always entirely successful at preventing a radar from locking on to its target. Select the additional techniques that can be used to help jamming achieve its aim._* **Select one or more:** a. Chaff b. Flares

**a. Chaff**

*_ESM1 - Consider the following statement:_* **An ELINT platform is able to extrapolate RF data to build a picture of the battle-space. With known information, it is able to identify types of threat, as well as distinguish friendly signals from the potential threat signals.** Select one: True False

**True**

Q1.4.3 - EW Doctrine Which of the following are classed as Cyber and Electromagnetic (CEMA) Activities? (Select one or more): Select one or more: a. Electronic Warfare operational support b. Electronic attack c. Cyber intelligence d. Battlespace spectrum management

**a. Electronic Warfare operational support** **b. Electronic attack** **c. Cyber intelligence**

*_MOD EW- Which MOD organisation will write a new Mission Dependent Data set for a platform RWR?_* **Select one:** a. 92 Sqn b. TASE c. JEWOSC Reprogramming

**c. JEWOSC Reprogramming**

*_Airbone Radar- At what frequencies would the Radar on a fast jet aircraft, operating in the Airborne Interceptor role, operate?_* Select one: a. 2 - 3 Ghz b. 6 - 8 Ghz c. 8 - 10 Ghz

**c. 8 - 10 Ghz**

Q4.4.2 - RF Missile Guidance The 3 types of homing guidance are:

Passive, semi-active and active.

*_LASER - The most common military use of LADAR is the helicopter wire avoidance system. What approximate thickness of wire will the high resolution detect?_* **Select one:** a. \< 10 mm b. \< 1 mm c. \< 100 mm

**a. \< 10 mm**

*_IADS- For an IADS to be truly effective, it needs to be able to quickly and efficiently complete the engagement chain. In order to do that, some key components are required - select the correct list from the choices below:_* **Select one:** a. Sensors, Communications, Weapons, Command and Control b. Sensors, Communications, Integration, Command and Control c. Scanners, Communications, Weapons, Command and Contro

**a. Sensors, Communications, Weapons, Command and Control**

Complete this sentence... IR Guidance- The wavelength on the EO portion of the spectrum **"... ... ..."** as the temperature of the item gets hotter, moving towards the visible portion of the EO spectrum and **"... ... ..."** in intensity.

IR Guidance- The wavelength on the EO portion of the spectrum [**decreases**] as the temperature of the item gets hotter, moving towards the visible portion of the EO spectrum and [**increases**] in intensity.

*_Jamming & Frequency Hopping_* *_What is the meaning of EPM?_* **Select one:** a. Electronic Protection Measures b. Electrical Pulse Monitoring

**a. Electronic Protection Measures**

Which of the following are factors of a Command to Line-of-Sight (CLOS) engagement system? Select one or more: a. Minimum Range b. Manoeuvrability of the missile c. Amount of Lateral Acceleration d. Number of fire channels

Minimum Range Manoeuvrability of the missile Amount of Lateral Acceleration Number of fire channels

*_Doppler- What are the first, second and third bind speeds of an MTI Radar operating at 4 Ghz, with a PRF of 2 kHz?_* Hint: V_n = (nλPRF) / 2 Select one: a. 75, 150 & 225 m/sec b. 150, 300 & 450 m/sec c. 50, 75 & 100 m/sec

a. 75, 150 & 225 m/sec f = 4 Ghz (4\*10⁹) PRF = 2 kHz (2000Hz) λ = c / f λ = (3\*10⁸) / (4\*10⁹) λ = 0.075 V₁ = (1 \* λ PRF) / 2 V₁ = (0.075 \* 2000) / 2 V₁ = 75 V₂ = 150 V₃ = 225

SEAD- Developed during the mid-80s, the [**?**] was a non-powered, glider decoy, capable of travelling in excess of 70 miles. The [**?**] is a variant of the same design, but includes a turbojet propulsion system, allowing it to fly a much greater distance, even at low altitudes.

SEAD- Developed during the mid-80s, the [**Tactical ALD (TALD)**] was a non-powered, glider decoy, capable of travelling in excess of 70 miles. The [**Improved TALD (ITALD)**] is a variant of the same design, but includes a turbojet propulsion system, allowing it to fly a much greater distance, even at low altitudes.

True or False Q8.5.7 - IR MANPADS The SA-7B is the only Former Soviet Union MANPADS in the development series that does not have a cooled seeker head.

True

*_MOD EW - Where can you find Tac Memos?_* **Select one:** a. Universal Tactics Manual (UTM) b. Global Strategic Trends c. Defence EW Database (DEWDB)

**a. Universal Tactics Manual (UTM)**

*_RF Missile Guidance- The 3 types of missile homing systems are:_* **Select one:** a. Passive, semi-active and active. b. Active, CLOS and COLOS. c. Passive, semi-active and CLOS.

**a. Passive, semi-active and active.**

*_IR Signature- Which of the following are methods of signature reduction on an aircraft?_* **Select one or more:** a. Airframe Shielding b. Baffles c. IR Suppression

**a. Airframe Shielding** **b. Baffles** **c. IR Suppression**

Basic Radar Concepts In Radar applications, [?] beam widths are necessary so that 2 or more targets can be discriminated from each other in azimuth or elevation. If the beam width is too wide, 2 targets will be seen as [?] return on the display. Narrow beam widths give the additional benefit of more gain in the main transmitted lobe, which will optimise the detection range.

Basic Radar Concepts In Radar applications, [**narrow**] beam widths are necessary so that 2 or more targets can be discriminated from each other in azimuth or elevation. If the beam width is too wide, 2 targets will be seen as [**one**] return on the display. Narrow beam widths give the additional benefit of more gain in the main transmitted lobe, which will optimise the detection range.

*_ESM1 - Which of the following is not a function of Electronic Support Measures (ESM)?_* **Select one:** a. Destroy b. Intercept c. Identify

**a. Destroy **

*_EM Fundamentals - Waves & Electrics_* *_The relationship between frequency, wavelength and the speed of light is expressed as:_* **Select one:** a. c = f λ b. f = 2c / λ

**c = f λ**

Q3.3.2.4 - Spread Spectrum & Encryption Frequency Hopping, Channel Multiplexing, Spectrum Spread and CDMA are all methods to defeat .............?

Jamming

Q2.3.4 - EO Fundamentals Which detector material is used to give the greatest range of wavelengths? Select one: a. MCT b. InSb c. PbS

**a. MCT**

MANPADS have been proliferated all around the globe, and there are thought to be around 1 million produced to date and over 500,000 still in existence - many of which are available on the black market. It is easier to ask which countries don't have access to MANPADS than to work out which do. Select one: True False

**True**

*_Spread Spectrum & Encryption_* *_In Direct Sequence Spread Spectrum, what is the repeating encoding signal called?_* **Select one:** a. Barker Code b. Chipping Code

**b. Chipping Code**

Synthetic Aperture Radar (SAR) and Track-while-scan (TWS) are scan types used by which type of aircraft?

Fighter and ground attack aircraft.

Data Links - Which of the following is not a Data link used by the military? **Select one:** a. Link-1 b. Link-16 c. Link-18

**c. Link-18**

**b. Pseudo-Imaging**

*_Further Modulation Techniques_* *_Consider the following statement:_* *_To ensure sufficient modulation signal information is imprinted onto the carrier signal the modulation signal must be sampled at a rate which is at least four times that of the highest frequency within the signal._* **Select one:** True False

**False**

Q4.3.5 - Airborne Radar Is the following statement True or False? A ground mapping scan can be used for navigation, allowing real world radar reflections to be overlayed on a map, so an operator can confirm navigational accuracy. This is particularly useful in an environment where GPS may get jammed.

True

*_Jamming & Frequency Hopping_* *_Label the major components of a rudimentary Jamming system._*

What is the main use of Doppler in Radar systems?

The main use of the Doppler effect in Radar systems is to measure the velocity of moving targets and to remove clutter returns caused by stationary objects.

Q3.1.7 - Antennas What is the main purpose of an Antenna?

Provide a means for the propagation of an EM transmission through the atmosphere.

Q4.1.1.4 - Basic Radar Concepts From the text below, identify the following Radar associated terms: This is inversely proportional to the pulse width. This is the frequency of the wave upon which modulation occurs. This Radar transmits a continuous stream of RF energy, normally using a separate antenna to receive echoes. This is the time from the start of one pulse to the start of the next.

**Bandwidth** This is inversely proportional to the pulse width. **Carrier Frequency** This is the frequency of the wave upon which modulation occurs. **Continuous Wave Radar** This Radar transmits a continuous stream of RF energy, normally using a separate antenna to receive echoes. **Pulse Repetition Interval** This is the time from the start of one pulse to the start of the next.

*_Complete the sentence..._* MWS- IR MWS detect **"... ... ..."** emissions from, for example, muzzle flashes and rocket motors. IR radiation is not scattered as much as UV so IR sensors can provide a higher **"... ... ..."** accuracy and relatively good performance under most atmospheric conditions.

MWS- IR MWS detect [**mid‑IR**] emissions from, for example, muzzle flashes and rocket motors. IR radiation is not scattered as much as UV so IR sensors can provide a higher [**AOA**] accuracy and relatively good performance under most atmospheric conditions.

*Complete the sentences...* [?] are when radar energy arrives at a conducting surface it sets up currents in that surface. These run around an aircraft and, because of the shape of the surface, re-radiate. [?] occur when surface currents move along the surface of an aircraft and encounter changes such as the gaps between panels or the edges of undercarriage doors, or just a change of material such as that which occurs at engine nozzles or at the edge of the canopy. This forms an accidental aerial and can propagate the RF energy in any direction, potentially back towards the radar.

[**Creeping Waves**] are when radar energy arrives at a conducting surface it sets up currents in that surface. These run around an aircraft and, because of the shape of the surface, re-radiate. [**Travelling Waves**] occur when surface currents move along the surface of an aircraft and encounter changes such as the gaps between panels or the edges of undercarriage doors, or just a change of material such as that which occurs at engine nozzles or at the edge of the canopy. This forms an accidental aerial and can propagate the RF energy in any direction, potentially back towards the radar.

Q2.1.11 - Decibels ## Footnote **What dB value would equate to half the power?**

-3 dB

_*RF ECM Drag and drop the responses to match the actions and complete the typical breaking of the Engagement Chain.*_ - avoiding/denying detection by ? - preventing/delaying acquisition by ? - prevent/delaying launch by ? - and finally countering the missile guidance by ?

- avoiding/denying detection by [Remaining Silent/Jamming EW/TAR/HF] - preventing/delaying acquisition by Identifying the threat and mode and transmitting false targets - prevent/delaying launch by Elevating priority and jamming the TT radar and missile seeker head - and finally countering the missile guidance by [Continuing to jam the TT radar and seeker head, but also deploying chaff and/or RF EADs]

*_Drag and drop the responses to match the ECM terminology._* *_Triangular Sweep / Sweep Period_* - The time taken to sweep the AM Frequency from its initial value to its final value. [?] - An AM frequency is swept from its initial value to its final value in a set period and then returned to its initial value over the same period. [?]

Drag and drop the responses to match the ECM terminology. - The time taken to sweep the AM Frequency from its initial value to its final value. [Sweep Period] - An AM frequency is swept from its initial value to its final value in a set period and then returned to its initial value over the same period. [Triangular Sweep]

*_EM Fundamentals - Waves & Electrics_* *_What type of current is provided by a battery?_* **Select one:** a. Direct Current b. Sinusoidal Current

**Direct Current**

*_IR Jamming - Which of the following describes when the aircraft remains within the missile FoV, but a miss distance is generated. If the jamming was subsequently switched off, the missile may be able to regain track on the target and so the jamming must be continuous until the missile has flown past the aircraft._* **Select one:** a. Optical break-lock b. Guidance Suppression c. IR Missile Tracking

**b. Guidance Suppression**

*_RF Missile Guidance - What are the four main stages of the RF Missile Guidance loop?_* **Select one:** a. Sensor Information, Error Calculation, Guidance Computer, Steering Command b. Sensor Information, Error Induction, Data Uplink, Modified Missile Boost c. Signal Reflection, Error Induction, Guidance Computer, Modified Missile Boost

**a. Sensor Information, Error Calculation, Guidance Computer, Steering Command**

*_MWS- Select 2 advantages of an IR MWS from the options below:_* **Select one or more:** a. Covert b. Potentially detects during entire missile flight c. Can see through any weather d. Cheap

**a. Covert** **b. Potentially detects during entire missile flight**

*_RF ECM_* *_What are the main 2 types of Jamming Systems?_* **Select one:** a. Analogue Repeater and Digital Radio Frequency Memory b. Analogue Replicator and Digital Receiver Frequency Modulation

**a. Analogue Repeater and Digital Radio Frequency Memory**

Q4.4.5 - RF Missile Guidance Which of the following are factors of a Command to Line-of-Sight (CLOS) engagement system? Select one or more: a. Number of fire channels b. Minimum Range c. Manoeuvrability of the missile d. Amount of Lateral Acceleration

**a. Number of fire channels** **b. Minimum Range** **c. Manoeuvrability of the missile** **d. Amount of Lateral Acceleration**

*_Antennas - What is the main purpose of an Antenna?_* **Select one:** a. Provide a means for the propagation of an EM transmission through the atmosphere. b. Provide a means to point a transmission in a specific direction. c. Limiting the frequency, gain and beam width of a transmission.

**a. Provide a means for the propagation of an EM transmission through the atmosphere.**

**a. High atmospheric attenuation levels**

**True**

*_Q9.1.5 - MOD EW Organisations_* *_Is the following statement True or False?_* 92 Sqn is based at HQ ASWC and develop tactical advice and training for the front line. 92 Sqn SMEs are responsible for the production of Tac Memos for front line units, which will furnish them with tactical advice on different theatres of operation or tactics, techniques and procedures (TTPs). Select one: True False

**True**

Q8.3.2.2 - Denial and Deception **Spot jammers** **Swept Spot jammers** **Search-lock jammers** **Barrage jammers** **?** can be used when accurate information about the victim radar’s frequency and bandwidth is known (either from Int or by using a real-time intercept receiver). With **?** the noise jamming signal can be swept across the entire range of frequencies over which the victim radar can hop, or can also be used when several radars are operating on similar frequencies. **?** are spot jammers capable of reacting to changing radar parameters. They are cued by fast-acting receivers and can jam over a wide range of frequencies. **?** act continuously over a wide frequency range, covering all the frequencies used by agile radars and thus can also jam several systems operating on similar frequencies at once.

**Spot Jammers** can be used when accurate information about the victim radar’s frequency and bandwidth is known (either from Int or by using a real-time intercept receiver). **Swept Spot Jammers** the noise jamming signal can be swept across the entire range of frequencies over which the victim radar can hop, or can also be used when several radars are operating on similar frequencies. **Search-Lock Jammers** are spot jammers capable of reacting to changing radar parameters. They are cued by fast-acting receivers and can jam over a wide range of frequencies. **Barrage jammers** act continuously over a wide frequency range, covering all the frequencies used by agile radars and thus can also jam several systems operating on similar frequencies at once.

Q4.1.2.3 - Pulsed Radar Fundamentals Fill in the blanks. In Secondary Radar systems, which can include **?** and AIS (Automatic Identification System), a radar sends a coded message to a **?** located on the target, which contains data to interrogate the aircraft. The target responds to the interrogation using a separate **?** operating at a different **?**.

In Secondary Radar systems, which can include **IFF** and AIS (Automatic Identification System), a radar sends a coded message to a **transponder** located on the target, which contains data to interrogate the aircraft. The target responds to the interrogation using a separate **transmitter** operating at a different **frequency**.

Q2.3.7 - EO Fundamentals Thermal Crossover generally occurs at what times of day? Select one: a. +/- 1 hr of Sunset & Midnight b. +/- 1 hr of Sunset & Sunrise c. +/- 1 hr of Sunrise & Midday d. +/- 1 hr of Midday & Midnight

**b. +/- 1 hr of Sunset & Sunrise**

*_Q8.4.3 - Which of the following platforms provides a jamming capability for a SEAD mission?_* **Select one:** a. EA-18G Growler b. Tornado ECR c. F-16CM

**a. EA-18G Growler**

Q3.3.1.5 - Jamming & Frequency Hopping Consider the following statement: Frequency hopping is one of the best methods for creating secure communications between two users. Select one: True False

**False**

*_Improved Target Detection_* **How are the best square waves generated?** Select one: a. By using multiple odd harmonics of sine waves. b. By using 10 harmonics of sine waves.

**a. By using multiple odd harmonics of sine waves.**

*Complete the sentence...* RF ECM The Engagement Chain is an adversaries attempt to Search for, Acquire , and [?] a target, before Launch of a weapon and producing an [?].

RF ECM The Engagement Chain is an adversaries attempt to Search for, Acquire , and [**Track**] a target, before Launch of a weapon and producing an [**Intercept**].

*_EO Fundamentals - Is the following statement True or False?_* *_When a metal rod is heated, the wavelength of the energy it emits gets shorter!_* **Select one:** True False

**True**

*_ESM1 - From the list below, which one is an advantage of a cavity-backed spiral antenna?_* **Select one:** a. 4 antennas will give an instantaneous 360o coverage. b. They have a gain of approximately 35 dB. c. They have a very narrow beam width.

**a. 4 antennas will give an instantaneous 360o coverage.**

*_Doppler- Using a Doppler Radar transmission, what 2 factors can be determined from a target echo?_* Select one: a. range & velocity b. range & bearing c. velocity & angle of attack

**a. range & velocity**

*_Antennas - Which of these Antennas are most suitable for aircraft UHF and VHF communications?_* **Select one:** a. Parabolic Reflector. b. Dipole Antenna. c. Blade Antenna.

**c. Blade Antenna.**

*_IR Manpads - The acronym MANPADS stands for:_* **Select one:** a. Man Portable Air Defence System b. Man Portable Area Defence System c. Man Portable Air Destruction System

**a. Man Portable Air Defence System**

*_Q4.6.3 - ESM 2_* *_An advantage of a Crystal Video Receiver (CVR) over a Super Hetrodyne Receiver (SHR) is that it is:_* **Select one:** a. Able to accurately determine the threat type from the Mission Dependant Data. b. Capable of instantaneous signal detection for a given frequency range.

**b. Capable of instantaneous signal detection for a given frequency range.**

*_Synthetic Aperture Radar_* **Identify a use of SAR:** **Select one or more:** a. Environmental monitoring. b. GPS location.

**a. Environmental monitoring.**

# *_Fill in the gaps..._* The Doppler effect is considered to be the change in **"... ... ..."** between the transmitted and received signal caused by the **"... ... ..."** of the target. If a target is producing a sound, there will be an **"... ... ..."** in the frequency of the sound as the target moves towards you.

The Doppler effect is considered to be the change in [frequency] between the transmitted and received signal caused by the [movement] of the target. If a target is producing a sound, there will be an [increase] in the frequency of the sound as the target moves towards you.

Q5.3.5 - IR MWS What are the advantages of a UV MWS?

Medium detection range capability Covert Relatively simple, cheap and mature

*_ESM 2 - An advantage of Super Hetrodyne Receiver (SHR) over Crystal Video Receivers (CVR) is that it is:_* **Select one:** a. More accurate in frequency measurement. b. Faster in response time.

**a. More accurate in frequency measurement.**

Q4.2.14 - Doppler What pulse characteristics can be used used to eliminate blind speeds?

a. pulse stagger b. multi-PRF values c. pulse jitter

* RF ECM* * At a certain range between the radar and jammer the reflected radar energy will be equal to the jamming energy. This is known as the _____________ and for any target within this range the jamming will be ineffective.* **Select one:** a. Burn Through Point b. Break Through Point

**a. Burn Through Point**

*_EM Fundamentals - Phase, Polarisation & Propagation_* *_What are the 3 main types of polarisation?_* **Select one:** a. Vertical, Horizontal and Circular b. Eliptical, Monopulse and Slanted

**Vertical, Horizontal and Circular**

*_EW in Space - Two of the following three statements are true and are advantages of P code over C/A code._* *_Choose the one statement which is false._* **Select one:** a. P code can be encrypted (Y code) to prevent spoofing. b. The wider bandwidth means that P code cannot be acquired in a jamming environment. c. The wider bandwidth means that P code is less susceptible to jamming.

**b. The wider bandwidth means that P code cannot be acquired in a jamming environment.**

**?** orbits are better for IMINT or ELINT due to their close proximity to the earth. **?** orbits are at a higher altitude ensuring that satellites have a bigger footprint on the ground. In general most satellites in this orbit are manoeuvred into a circular orbit with a period of 12 hours. This means that they will orbit the earth twice a day (known as semi-synchronous). **?** orbits are where spacecraft complete one full orbit around the earth at the same speed as the earth completes one full rotation on its axis every 24 hours. **?** orbits are placed in such a way that the satellite at its apogee (point furthest from the Earth) will spend a long period of time looking at only a single point of the earth.

**LEO** orbits are better for IMINT or ELINT due to their close proximity to the earth. **MEO** orbits are at a higher altitude ensuring that satellites have a bigger footprint on the ground. In general most satellites in this orbit are manoeuvred into a circular orbit with a period of 12 hours. This means that they will orbit the earth twice a day (known as semi-synchronous). **GEO** orbits are where spacecraft complete one full orbit around the earth at the same speed as the earth completes one full rotation on its axis every 24 hours. **HEO** orbits are placed in such a way that the satellite at its apogee (point furthest from the Earth) will spend a long period of time looking at only a single point of the earth.

*_Q8.1.4 - Consider the following statement:_* *_Israel is a good example of a country with a combined aircraft and missile defence IADS._* **Select one:** True False

**False**

Q2.2.2.5 - Phase, Polarisation & Propagation What are the 3 main types of polarisation? Select one: a. Eliptical, Monopulse and Slanted b. Vertical, Horizontal and Circular c. Parallel, Spiral, and Linear d. Sinusoidal, Triangular and Ramped

**b. Vertical, Horizontal and Circular**

*_IR Expendable Decoys - Identify the 4 methods of flare rejection:_* **Select one:** a. Kinematic, Intensity, Spectral, Spatial b. Kinematic, Interruptive, Spectral, Spatial c. Kinematic, Interruptive, Special, Spatial

**a. Kinematic, Intensity, Spectral, Spatial**

Q8.3.3.3 - RF ECM On-Board Techniques What is the ECM monitoring technique below called: This monitoring technique is used where there is enough isolation between the jammer receiver / transmitter frequency range, or antenna coverage patterns, to allow the receiver to operate whilst the jammer continues to transmit.

Look-Over

*_Doppler - What is the term used when the amount of Doppler shift exactly coincides with the PRF of the Radar transmission?_* **Select one:** a. blind speed b. maximum unambiguous range c. eclipsing

**a. blind speed**

Q4.2.7 - Doppler The returns from which of the following objects would not be removed as clutter using MTI processing on a PPI? Select one: a. Chaff b. Ground returns c. Trees d. Buildings

**a. Chaff**

*_Basic Target Detection_* *_What the maximum unambiguous range of a target for a EW Radar using a pulse repetition interval (PRI) of 1 mS?_* **Select one:** a. 15 km b. 150 km

**b. 150 km**

* Complete the sentences...* * IR Expandable Decoys - [**?**] is when a flare must ignite quickly so that it is sufficiently bright whilst in the missile’s FoV before falling away to decoy the seeker head successfully.* * The flare must have a long enough [**?**] that the aircraft can remain outside the seeker FoV and thus the missile cannot re-acquire the aircraft once the flare has burnt out.*

IR Expandable Decoys - [**Rise Rate**] is when a flare must ignite quickly so that it is sufficiently bright whilst in the missile’s FoV before falling away to decoy the seeker head successfully. The flare must have a long enough [**Burn Time**] that the aircraft can remain outside the seeker FoV and thus the missile cannot re-acquire the aircraft once the flare has burnt out.

True or False The minimum detectable range is the smallest range from which a transmitted radar pulse can be reflected, and received, before the next pulse is transmitted.

False The Minimum Range that can be measured by a pulse radar system is determined not only by the width of the transmitted pulse signal, (the radar cannot receive at the same time as transmitting), but also by the Transmitter / Receiver (TR) cell recovery time, tTR, as the duplexer (antenna switching unit) cannot switch from transmit to receive instantaneously.

Pulsed Radar Fundamentals Drag and drop the individual lines to complete the correct sequence of events for a Pulse Radar: [A tiny portion of the reflected energy is collected by the radar antenna and routed to the receiver for processing.] [The transmitted energy is intercepted by the target and reflected in many directions.] 1. A transmitter generates burst of RF that is radiated into space by an antenna. 2. 3. 4. The receiver knows when the transmitter sent out the pulse of RF and can measure how long it took for the echo to return.

Pulsed Radar Fundamentals Drag and drop the individual lines to complete the correct sequence of events for a Pulse Radar: 1. A transmitter generates burst of RF that is radiated into space by an antenna. 2. [The transmitted energy is intercepted by the target and reflected in many directions.] 3. [A tiny portion of the reflected energy is collected by the radar antenna and routed to the receiver for processing.] 4. The receiver knows when the transmitter sent out the pulse of RF and can measure how long it took for the echo to return.

*Complete the sentence...* RF ECM [?] is the division of electronic warfare which involves actions taken to prevent or reduce an enemy's effective use of the electromagnetic spectrum through the use of electromagnetic energy.

RF ECM [**Electronic Countermeasures]** is the division of electronic warfare which involves actions taken to prevent or reduce an enemy's effective use of the electromagnetic spectrum through the use of electromagnetic energy.

Q4.1.2.6 - Pulsed Radar Fundamentals Which of the following Radar system is classed as a secondary Radar? Select one: a. Missile Illumination Radar b. Target Tracking Radar c. Early Warning Radar d. Identification Friend or Foe (IFF)

**d. Identification Friend or Foe (IFF)**

The purpose of putting an IR-suppressant additive into jet fuel mix is to reduce the overall IR energy output and thus avoid detection. Select one: True False

**False**

*_Airbone Radar- At which frequencies would you expect the Radar on an EW aircraft, such as the Sentry, to operate?_* **Select one:** a. 2 - 4 GHz b. 4 - 6 GHz c. 8 - 10 GHz

**a. 2 - 4 GHz**

# Fill in the gaps... Q1.2.10 - EW Definitions **?** information is data that has been processed only to the extent required to immediately identify and/or locate the source of the adversary signal. As such, ESM focuses on parametric information **?** to the actual content of the communications. **?** on the other hand, is data generally derived from the **?** content of the collected signal. It may require technical applications, such as demodulation or other processing of complex signals, and will almost always result from the analysis of the content of the information.

Q1.2.10 - EW Definitions **ESM** information is data that has been processed only to the extent required to immediately identify and/or locate the source of the adversary signal. As such, ESM focuses on parametric information **external** to the actual content of the communications. **SIGINT** on the other hand, is data generally derived from the **internal** content of the collected signal. It may require technical applications, such as demodulation or other processing of complex signals, and will almost always result from the analysis of the content of the information.

*_EW in Space - Two of the following three statements are true and are advantages of P code over C/A code._* *_Choose the one statement which is false._* **Select one:** a. The wider bandwidth means that P code cannot be acquired in a jamming environment. b. P code can be encrypted (Y code) to prevent spoofing. c. The wider bandwidth means that P code is less susceptible to jamming.

**a. The wider bandwidth means that P code cannot be acquired in a jamming environmen**

*_Improved Target Detection_* **What is shown in the FM Pulse Compression (Chirp) image below?** Select one: a. Upsweep. b. Multiple Harmonics.

a. Upsweep.

*_IR Guidance - Is the following statement True or False?_* *_When considering sources of IR energy from an aircraft, exhaust gases in the plume produce most of the IR energy seen in the Band 4 portion of the spectrum._* **Select one:** True False

**True**

*_EW in Space- Which of the following statements about GPS is False?_* **Select one:** a. Receiver position is calculated by accurately determining distances from several satellites. b. C/A code is vulnerable to jamming but P code cannot be jammed.

**b. C/A code is vulnerable to jamming but P code cannot be jammed.** **FALSE**

Q3.2.1.5 - Basic Modulation Techniques What output frequencies would be produced by mixing a 50Hz input signal with a 225kHz local oscillator signal? Select one: a. 50Hz, 224.95kHz, 225kHz, 225.05kHz b. 50kHz, 175kHz, 225kHz and 275kHz c. 50Hz, 224.5kHz, 225kHz, 225.5kHz d. 50Hz, 175kHz, 225kHz and 275Hz

**a. 50Hz, 224.95kHz, 225kHz, 225.05kHz**

*_Improved Target Detection_* **What is shown in the image below?** Select one: a. Polyphase Coded Pulse Compression. b. Barker Coded Pulse Compression.

**b. Barker Coded Pulse Compression.**

*Complete the sentence...* IR Jamming - The aim of an IR jammer is to distort the guidance information derived by an IR missile seeker, causing the missile to miss its intended target. Airborne IR jammers can provide [**?**] continuous protection and are [**?**].

IR Jamming - The aim of an IR jammer is to distort the guidance information derived by an IR missile seeker, causing the missile to miss its intended target. Airborne IR jammers can provide [**pre‑emptive]** continuous protection and are [**visually covert**].

Basic Radar Concepts From the text below, identify the following Radar associated terms: This is inversely proportional to the pulse width. [?] This is the frequency of the wave upon which modulation occurs. [?]

Basic Radar Concepts From the text below, identify the following Radar associated terms: This is inversely proportional to the pulse width. [**Bandwidth**] This is the frequency of the wave upon which modulation occurs. [**Carrier** **Frequency**]

*_Denial and Deception_* *_Select the correct subdivisions of ECM._* **Select one or more:** a. Jamming b. Neutralisation c. Deception d. Identification

**a. Jamming** **b. Neutralisation** **c. Deception**

*_Use of EO - What are the 3 types of EO systems?_* **Select one:** a. TV, IR and Image Intensifiers b. IR, Telescopes and Image Intensifiers c. UV, Binoculars and Telescopes

**a. TV, IR and Image Intensifiers**

*_Q2.1.3 - Decibels_* Using the calculator method, convert 35 dB to a number (2 decimal places).

3162.28

Q8.2.3 - RF Signature Reduction When Narrow Band RAM is used on an aircraft, what change in wavelength (λ) would effectively neutralise the returning signal?

λ/2

*_MOD EW - What is the main role of the Air Warfare Centre?_* **Select one:** a. To provide Integrated Mission Support. b. To provide Mission Data Sets. c. To manage the Defence EW Database.

**a. To provide Integrated Mission Support.**

*_RF ECM_* *_What would be the theoretical power loss (in decibels) for a jamming signal that has a total polarisation mismatch with a radar receiver?_* **Select one:** a. -26 dB b. - 100 dB

**a. -26 dB**

*_Basic Modulation Techniques_* *_Is the following statement True or False?_* *_The process of mixing an audio frequency signal with a higher transmission frequency is known as Modulation._* **Select one:** True False

**True**

*_RF Missile Guidance - Which of the following is not a typical limitation of a Command to Line-of-Sight (CLOS) engagement zone?_* **Select one:** a. Proportional Navigational Guidance b. Minimum Range c. Manoeuvrability of the Missile

**a. Proportional Navigational Guidance**

Basic Radar Concepts The scattering of the beam at the edges of the parabolic dish is referred to as [?], and the scattering of the beam when it hits the feed horn is called [?]. Antenna designers spend a huge amount of effort in attempting to minimise these anomalies.

Basic Radar Concepts The scattering of the beam at the edges of the parabolic dish is referred to as [**diffraction**], and the scattering of the beam when it hits the feed horn is called [**refraction**]. Antenna designers spend a huge amount of effort in attempting to minimise these anomalies.

*_Improved Target Detection_* **Barker coded pulse transmissions differ from FM coded pulse transmissions, as the technique uses a bi‑phase (0º and 180º) PSK modulation code to switch the phase of the pulses modulating signal.** Select one: True False

True

Q7.1.3 - LASER Which of the following statements about the safety of Lasers is incorrect? Select one: a. All lasers can damage the eye if sufficiently powerful but visible and near IR frequencies are most dangerous because they are passed by the cornea to the retina. b. A laser-warning receiver will not prevent eye damage. c. Most laser visors / spectacles work by using filters tuned to absorb a limited number of likely threat frequencies. d. The damage to the human eye from a pulsed non eye-safe laser is directly proportional to the length of the laser flash

**d. The damage to the human eye from a pulsed non eye-safe laser is directly proportional to the length of the laser flash**

*_SEAD - SEAD is an acronym for:_* **Select one:** a. Suppression of Enemy Air Defence b. Subversion of Enemy Air Defence c. Suppression of Extra Air Defence

**a. Suppression of Enemy Air Defence**

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