Weapons - Objectives Flashcards
Discuss and list IR target-detection factors to include sources of aircraft heating, the effects of background IR sources and atmospheric attenuation on target acquisition.
Factors include sources of IR energy, aspect angle, range background IR effects, atmospheric attenuation.
Sources of aircraft heating are reflected energy, aerodynamic heating, hot metal and exhaust plume. Benign background=no competition with target IR signal; determined by seeker sensitivity.
Adverse background=competing IR signal; determined by seeker discrimination capability and S/N ratio.
State the primary purpose of the detector in an IR-guided missile.
Convert modulated IR energy to an electrical signal. Determines the AA the missile can be fired, the range it can lock-on, the missile inherits detector’s weakness.
Discuss the properties of different detector materials. List types of detector materials.
Lead sulfide (PbS) - Cooled 2.9-3.9 micron Lead Selenide (PbSe) - Cooled 3-4.2 micron Indium Antimonide (InSb) - Cooled 3.5 - 5.5 micron (most in tune with aircraft heating ranges)
State why detector materials are cooled, methods of cooling and the impact detector cooling has on IR-guided missile capabilities.
Improves detector sensitivity and lowers required threshold relative to background IR radiation.
Electrically or with cryogenic gas
State the primary purpose of the reticle in an IR-guided missile.
Modulates IR energy via opaque and clear tracking windows and varies output of the electrical signal sent to the GCS based upon where the IR energy hits the reticle.
Discuss how a reticle is used to create AM and FM signals.
AM: Measure 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.
Discuss spin scan reticles and list their disadvantages.
Spinning reticle, one detector using AM processing.
Disadvantages: Null area in center of reticle, vulnerable to IR jammers, flares in FOV longer.
Discuss conical scan reticles and list their advantages.
Spinning mirror, fixed reticle, one detector using FM processing.
Advantages: more precise tracking, seeker continuously sees target, more resistant to IR jammers, flares fall out of FOV quicker.
Discuss imaging arrays in IR-guided missiles.
Thousands of detector elements creates an IR picture. Increases sensitivity; greater lock-on range. Has high resolution with robust IRCCM.
List the three steps involved in IR-guided missile IRCCM.
Detect, Confirm, Counter
Discuss different IRCCM techniques.
FOV: decreases possibility of seeing flare
Bias Ahead: decreases possibility of seeing flare
Push-pull: push toward target, pull away from flare
Sector attenuation: filters out sector that sees flare
Discuss semi active radar missile guidance, state the primary characteristic and discuss the inherent advantages and disadvantages of each.
Semi active: Aircraft radar tracks the target while the missile homes in on the reflected radar energy. Missile has radar receiver but no transmitter.
Advantages: Resistant to EA designed to deny range info, decreases minimum range, accurate at longer ranges
Disadvantages: Requires reference Doppler be sent to missile prior to launch, must maintain lock on target (chaff/notch may cause it to break lock), limits max range due to LOBL, shooter must maintain target lock thru TOF.
Discuss different A/A missile control fin layouts, thrust vector control and rocket motors.
Tail control is more effective at high AOA when missile is slow.
Canard control is more effective at low AOA when missile is fast.
Thrust vectoring allows high turn rates, but only while motor is still burning.
Describe the characteristics of different missile flight profiles and state why pro-nav is advantageous.
Lag: missile points behind the target
Pure: missile points at the target
Pro-nav: missile points ahead of target, most energy efficient profile maximizing missile range and maneuverability.
Discuss A/A missile fuzing and warheads.
Contact fuze requires…contact.
Proximity fuze can initiate explosion from laser, RF or rapid change in seeker off-boresight angle.
Warheads include continuous rod and blast frag warhead.
Discuss and list considerations in A/A missile employment and factors that drive min and max employment ranges for A/A missiles.
Kinematic envelope (how far missile can travel), acquisition envelope (how far the target can be detected), altitude (higher altitude increases range but decreases missile maneuverability)
Define F-pole, MAR (E-pole), A-pole and min notch range.
F-pole: range from fighter to target when missile impacts
A-pole: Range from fighter to target when active missile acquires the target with its own radar and requires no support from launching aircraft.
MAR (E-pole): min range from a threat aircraft that a drag can be accomplished to kinematically defeat any missile the bandit could have launched
Min notch range: Min range from a threat aircraft that a notch maneuver can be accomplished
Discuss active radar missile guidance, state the primary characteristic and discuss the inherent advantages and disadvantages of each.
Missile has its own transmit and receive radar and onboard inertial guidance system.
Advantages: Accurate at long range, difficult to jam, L&L capability, multi-targeting.
Disadvantages: Complex, jamming against TTR may be effective prior to missile acquiring target
State why booms are included in the US weapons arsenal.
Incapacitate the enemy and/or prevent them from using their resources to engage US interests. Targets include anyone/anything vulnerable to kinetic energy released by chemical or nuclear explosions.
Describe an HE detonation and how it differs from a low-order deflagration.
HE detonation sustains a detonation shockwave to produce a powerful blast effect.
Deflagration is a rapid combustion; propagation wave is less than speed-of-sound.
