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1.2.5 Missile configuration

TheDog edited this page Aug 21, 2017 · 26 revisions

Note: this is not (yet) an exhaustive description of all missile parameters, but rather a quick reference which parameters are the most important one to simulate certain classes of missiles (by guidance type)

Missile classes by guidance / targeting type

All missiles (including bombs, torpedos and other ship/sub launched weapons) share some configuration options which are not discussed in detail here, but are very important to set properly:

  • Model/sound: exhaustPrefabPath, boostExhaustPrefabPath, boostExhaustTransformName, rotationTransformName, explModelPath, deployAnimationName, boostTransformName, audioClipPath , boostClipPath
  • General part configuration: shortName, waterImpactTolerance
  • Aerodynamics/agility/performance: thrust, cruiseThrust, boostTime, cruiseTime, cruiseDelay, optimumAirspeed, liftArea, steerMult, torqueRampUp, aeroSteerDamping, maxTorque, maxAoA, maxTurnRateDPS, spoolEngine, hasRCS, rcsThrust, deployedDrag, deployTime, useSimpleDrag, simpleDrag, simpleStableTorque, decoupleBoosters, boosterDecoupleSpeed, boosterMass
  • Warhead/damage & detonation properties: blastHeat, blastPower, blastRadius , proxyDetonate, DetonationDistance, detonationTime
  • Missile performance envelope: minStaticLaunchRange, maxStaticLaunchRange, minLaunchSpeed, maxOffBoresight, lockedSensorFOV, missileRadarCrossSection
  • Guidance specific parameters (more details below): missileType, targetingType, homingType, torpedo, guidanceActive
    • Cruise missile specifics: terminalManeuvering, terminalGuidanceType, terminalGuidanceDistance
    • AGM missile specifics: agmDescentRatio
    • Ballistic missile specifics:
    • Laser guidance specifics: beamCorrectionFactor, beamCorrectionDamping
    • Heat guidance specifics: heatThreshold, allAspect
    • Radar guidance specifics: radarLOAL, activeRadarRange, activeRadarLockTrackCurve
    • Anti-Radar guidance specifics:
  • Deprecated fields, dont need to set: activeRadarMinThresh, isSeismicCharge, indirect

All guided missiles must have guidanceActive = true and a valid targetingType and homingType set, or all the beautifully set guidance parameters wont have any effect...


Radar guided missiles

With radar guidance, three different types of missiles can be modeled:

1) SARH (semi-active radar homing)

A semi-active radar missiles does not have its own active radar emitter. Instead it relies on constant target illumination by the launching craft to be guided to its target. Works the same whether the actual missile is used in air-2-air, air-2-ground or surface-2-air scenarios, and also applies to torpedos (see below).

Real-world examples: Older air-2-air missiles (AIM-7 Sparrow, R27), many SAMs (PAC-3, SM1, SM2, RIM-162 ESSM)

Specific guidance parameters:

  • guidanceActive = true
  • targetingType = radar
  • homingType = aam //for radar you usually want the air target intercepting flight path. In some instances "agm" might work too, though...
  • activeRadarRange = 0 //this declares that the missile does not have its own active radar
  • radarLOAL = false //lock-on-after-launch is NOT supported for semi-active radar missiles!

The advantage of semi-active homing is that the missile itself does not emit signals, and is thus visible only with its static missileRadarCrossSection size on enemy radar.

2) Mixed SARH / active seeker:

The missile has an active seeker, but a launch range that is much higher than the active seeker radar range. Hence the missile CAN be launched at far range but then requires initial semi-active guidance until it can activate its own seeker and guide itself to the target. When launched at short range the seeker might become active immediately, thus making the missile fire&forget.

Real-world examples: Many air-2-air missiles (AIM-120 AAMRAM, R77), some SAMs (SM-3, SM-6)

Specific guidance parameters:

  • guidanceActive = true
  • targetingType = radar
  • homingType = aam //for radar you usually want the air target intercepting flight path. In some instances "agm" might work too, though...
  • activeRadarRange = something >0 and <maxStaticLaunchRange //this declares that the missile does have an active radar, but with limited range only
  • radarLOAL = true or false //depending on exact purpose/capability: with LOAL=true it might deviate from the assigned target and lock onto something else...
  • activeRadarLockTrackCurve //optional, declare the exact capabilities of the active radar. Default curve created if not set.
  • maxOffBoresight and lockedSensorFOV to values in degree to define how much the seeker can see in its field of view

While the missile is still passive, its radar signature is missileRadarCrossSection on enemy radar. After it has become active, it is immediately fully visible (and lockable) on enemy radars.

Two different "subtypes" of missile can be created by setting radarLOAL: if false, the missile's active seeker will only track the target that was assigned before launch by the launching vessel. If true, the radar seeker will lock onto anything it deems suitable... (including friedlies if they are unfortunate enough to be in the way and emit the strongest radar signal...)

3) True Fire&Forget

The missile has an active seeker with the same range (or even higher range) than maxStaticLaunchRange. The missile becomes active after launch immediately, allowing the firing vessel to turn away and/or lock something else.

Real-world examples: Aster, MICA

Specific guidance parameters:

  • guidanceActive = true
  • targetingType = radar
  • homingType = aam //for radar you usually want the air target intercepting flight path. In some instances "agm" might work too, though...
  • activeRadarRange = >=maxStaticLaunchRange //this declares that the missile does have an active radar, and should use it immediately
  • radarLOAL = true or false //depending on exact purpose/capability: with LOAL=true it might deviate from the assigned target and lock onto something else...
  • activeRadarLockTrackCurve //optional, declare the exact capabilities of the active radar. Default curve created if not set.
  • maxOffBoresight and lockedSensorFOV to values in degree to define how much the seeker can see in its field of view

The missile will be active right after launch, and hence immediately fully visible (and lockable) on enemy radars.

Regarding LOAL the same as for (2) applies.


Cruise missiles (GPS + optional terminal guidance)

1) Fixed-target cruise missiles

This defines a Tomahawk-style cruise missile that will fly to a fixed GPS coordinate and strike it, regardless if an enemy craft is at that position or not.

Specific guidance parameters:

  • guidanceActive = true
  • targetingType = gps
  • homingType = cruise //in some instances "agm" or "agmballistic" might also work
  • terminalManeuvering = true or false //terminal maneuvering makes the missile more difficult to intercept, but be cautious with using this on super-sonic missiles, as the hard maneuvers might throw the missile off course at the last moment without chance to correct before impact! Missiles with this also need to have a lot higher break up force than for a normal missile, as violent maneuvers might cause it to break up before reaching the target.

2) Cruise missiles with terminal guidance (esp. anti-ship cruise missiles)

Since ships are often moving targets, anti-ship cruise missiles usually have a terminal guidance mode (real world: radar or heat usually) and use the GPS cruise guidance only to get in range, then activate their seekers.

Supported terminal guidance seekers are:

  • Radar
  • Heat
  • Anti-Radar

Specific guidance parameter setup:

  • guidanceActive = true
  • targetingType = gps
  • homingType = cruise //in some instances "agm" or "agmballistic" might also work
  • terminalManeuvering = false //strongly advised to disable maneuvering, as this might make the seeker loose its target!
  • terminalGuidanceDistance = >0 //distance in m before the gps coordinate where the terminal guidance should activate
  • terminalGuidanceType = radar | heat | antirad //choose one

once the terminal guidance type is set and the missile reaches the destination coordinates (minus terminal guidance distance), it will behave as if it was a radar/heat/antiradar missile in the first place!

Hence, for the missile to function correctly with the configured terminal guidance mode, depending on the mode some additional parameters need to be set!

Radar terminal guidance: need to configure the active seeker:

  • activeRadarRange = >0
  • radarLOAL = true //otherwise will never lock anything
  • activeRadarLockTrackCurve //optional
  • maxOffBoresight and lockedSensorFOV to values in degree //advised to set HIGHER VALUES than normally found on AAMs, to ensure the seeker will find a target that maneuvers tangentially away from the missile

Heat terminal guidance: need to configure the heat seeker:

  • heatThreshold = value //sensitivity of the seeker - ground target without large engines are relatively "cool", so set lower threshold than for AAMs
  • allAspect = true or false //little effect here, allows for uncaged IR lock by radar when used in AAM context
  • maxOffBoresight and lockedSensorFOV to values in degree //advised to set HIGHER VALUES than normally found on AAMs, to ensure the seeker will find a target that maneuvers tangentially away from the missile

Anti-Radar terminal guidance: currently nothing to configure


ICBMs / ballistic missiles

todo


Other air-to-air guided missiles

1) Heat seeking missiles

Specific guidance parameters:

  • guidanceActive = true
  • targetingType = heat
  • homingType = aam //for heat seeking you usually want the air target intercepting flight path. In some instances "agm" might work too, though...
  • heatThreshold = value //sensitivity of the seeker - better seekers have lower thresholds
  • allAspect = true or false //if true it simulates a modern IR missile with "uncaged lock" ability. Even if the target is not within boresight fov, it can be radar locked and the target information transfered to the missile. It will then try to lock on with the heat seeker. If false, it is an older missile which requires a direct "in boresight" lock.
  • maxOffBoresight and lockedSensorFOV to values in degree

IR VLS usage: if you want to fire IR missiles from a vertical launch system (VLS), this can be achieved by setting allAspect = true and maxOffBoresight = 180. The missile will get its target information from the radar lock, and after vertical launch can still detect the target thanks to the large offboresight radius. Real-world example: SA Navy Umkhonto-IR missile


Other air-to-ground guided missiles

1) SALH (semi-active laser homing)

todo

2) Passive radar homing (anti-radar homing)

todo


Other ground-to-ground guided & unguided missiles

todo


Bombs (guided and unguided)

todo


Torpedos (guided and unguided)

todo


Other ship and submarine launched weapons (SLW)

todo