Air to Air Missiles

Question 1

Discuss and List IR target detection factor: aircraft heating.

Answer 1

Exhaust plume

Hot metal

Reflected Energy

Aerodynamic heating

Question 2

Discuss and List IR target detection factor: the effects of background IR sources

(FOOTSTOMP)

Answer 2

BENIGN: Cool background. No competition with target IR signal.

Determined by seeker sensitivity.
EX: Blue sky, night, dark clouds, choppy water

ADVERSE: Hot background. Competing IR sources with target signal.

IR envelope determined by seeker discrimination capability and S/N ratio.
EX: Hot Desert, Sunlit clouds, sun, sun reflection on smooth water.

Question 3

Discuss and List IR target detection factor: atmospheric attenuation on target acquisition.

Answer 3

Due to conditions that partially absorb or totally block IR energy such as moisture, dust, smoke, clouds, chemical compounds.

Question 4

State the primary purpose of the detector in an IR guided A/A missile.

(FOOTSTOMP)

Answer 4

Converted MODULATED IR energy to an electrical signal.

Question 5

Discuss the properties of different detector materials.

Answer 5

Wavelength=AA at which the missile can be fired

Sensitivity=Lock-on range

Question 6

List types of detector materials.

Answer 6

Lead Sulfide (PbS)
Lead Selenide (PbSe)
Indium Antimonide (InSb)

Question 7

State why detector materials are cooled

Answer 7

Improves detector sensitivity

Lowers require threshold relative to background radiation.

Question 8

Methods of cooling a detector

Answer 8

Electrical

Cryogenic Gas

Question 9

Discuss how a reticle is used to create Amplitude Modulation (AM) and Frequency Modulation (FM) signals.

Answer 9

AM: Measure the AMOUNT of IR energy passing through each individual transparent spoke of the reticle.

FM: Measures how much TIME IR energy spends on each individual transparent spoke of the reticle.

Question 10

Discuss spin scan reticles and list their disadvantages.

Answer 10

Spin scan spins around the center of reticle.

Spin scan (AM) Disadvantages: Null area in center of the reticle, Vulnerable to IR jammers, flares in FOV longer.

Question 11

Discuss conical scan reticles and list their advantages.

Answer 11

Conical scan spins around the target.

Conical Scan (FM) Advantages: More precise tracking of target, seeker continuously sees target, more resistant to IR jammers, flares fall out of FOV quicker.

Question 12

Discuss imaging arrays in IR-Guided a/a missiles

Answer 12

Focal Plane Array (FPA) is thousands of detector elements (no reticle). Creates and IR picture. Increased sensitivity, high resolution, robust IRCCM.

Question 13

List the three steps involved in IR-guided missile IRCCM

FOOTSTOMP

Answer 13

Detect

Confirm

Counter

Question 14

Discuss different IRCCM techniques

FOOTSTOMP

Answer 14

Response: Memory, step to another technique

FOV: Small instantaneous FOV or electronic FOV (never see the flare)

Spatial: Ability to discern two separate IR sources in the FOV

Kinematic/temporal: Assumes flares fall backwards (biases seeker towards forward target)

Spectral: multiple detectors look in different wavelengths.

Imaging systems: If it doesn’t look right…

Question 15

Discuss semiactive radar missile guidance, state the primary characteristic.

(FOOTSTOMP)

Answer 15

Missile has a radar receiver but no transmitter. Target is illumincated by Continuous wave (CW) or High Powered PRF (HPRF) from launching aircraft.

Characteristic: Aircraft Radar Tracks the target while the missile homes in on the reflected radar energy.

Question 16

Discuss semiactive radar missile guidance, state the primary characteristic.

(FOOTSTOMP)

Answer 16

Missile has a radar receiver but no transmitter. Target is illuminated by Continuous wave (CW) or High Powered PRF (HPRF) from launching aircraft.

Characteristic: Aircraft Radar Tracks the target while the missile homes in on the reflected radar energy.

Question 17

List semiactive radar missile guidance inherent advantages and disadvantages.

(FOOTSTOMP)

Answer 17

Advantages:

• resistant to EA designed to deny range information
• Can be guided almost immediately after launch-decreases minimum range
• Can compute its own course corrections

Disadvantages:

• Requires reference Doppler be sent to the missile before launch
• Must maintain lock onto the target Doppler
• Missile that requires seeker lock-on before launch limits maximum range
• Shooter must maintain target lock throughout missile TOF

Question 18

Discuss active radar missile guidance, state the primary characteristic.

Answer 18

Missile is sent information of target from launching aircraft by datalink until missile is close enough to target to tx/rx itself.

Primary Characteristic: Missile has its own transmit and receive radar.

Question 19

List active radar missile guidance inherent advantages and disadvantages.

(FOOTSTOMP)

Answer 19

Advantages:

• Difficult to jam
• Launch and leave capability
• multitargeting

Disadvantages:

• Complex
• Jamming against TTR may be effective prior to missile radar acquiring target.

Question 20

Discuss different A/A missile control fin layouts, thrust vector control (TVC), and rocket motors.

Answer 20

Tail Control: More effective at high AOA (when missile is slow)

Canard Control: Most effective at low AOA (when missile is fast)

Thrust Vector Control (TVC): Six types of TVC. Controlling movement by altering thrust direction.

Rocket Motors: Four types. Different types allow for different burn rates and speed.

Question 21

Describe the characteristic of different missile flight profiles

Answer 21

Three types of missile flight profile:
Lag: missile points behind the target

Pure: missile points at the target

Lead/pro-nav: missile points ahead of target.

Question 22

Discuss and list considerations in A/A missiles employment

Answer 22

Motor: Only burns for a few seconds, then begins to slow down

Drag: Higher or lower drag affect range and speed.

Launch to Eject (LTE) delay: After launch command their is a finite amount of time to when missile actually launches

Arming Delays: after launching there is a finite amount of time until missile is fully armed

guidance enable: missile flies straight before beginning to maneuver

Guidance Life: internal power source only provides power for so long

Fuzing: is the fuzing fast enough to detonate

Missile Maneuverability: can the missile maneuver to intercept the target.

Question 23

List factors that drive minimum and maximum employment ranges for A/A missiles (DISCUSS IS A ANOTHER QUESTION)

(FOOTSTOMP)

Answer 23

Minimum range considerations:

• Launch to eject (LTE) delays
• Guidance enable
• arming delays
• fuzing
• missile maneuverability
• gimbal limits

Maximum range considerations:

• Target detection
• Motor (endgame)
• Drag (Endgame)
• Guidance life
• Altitude

Question 24

List the different fin controls.

Answer 24

Tail

Canard

Wing

Thrust Vector Control (TVC)

Question 25

State why proportional navigation is advantageous.

Answer 25

Most energy efficient.

Maximize missile range

Maximizes missiles endgame maneuverability.

Question 26

What are the effects of altitude on A/A missiles

FOOTSTOMP

Answer 26

• High-to-low increases range
• Low-to-high decreases range
• Missiles not as maneuverable at high altitude

Question 27

To exploit a targets IR and Radar energy, missile must…

Answer 27

IR:

• Sense Target–Detector
• Track Target–Optical System
• Hit Target–Flight Profile
• Ignore–IRCCM

Radar:

• Sense Target–Shooter’s radar
• Track Target–shooter’s radar/onboard radar
• Hit Target–Guidance/tracking/flight profile
• Ignore–EP

Question 28

To exploit a targets IR and Radar energy, missile must…

Answer 28

IR:

• Sense Target–Detector
• Track Target–Optical System
• Hit Target–Flight Profile
• Ignore flares–IRCCM

Radar:

• Sense Target–Shooter’s radar
• Track Target–shooter’s radar/onboard radar
• Hit Target–Guidance/tracking/flight profile
• Ignore EA–EP