Active Radar Missiles Always Know Target Location

[NeedzWD40]

Hi,

 

Currently, all air-to-air missiles using active radar guidance know their target location and do not need guidance from host aircraft until pitbull. You can lock a target, fire, then break lock or turn cold and the missile will maintain last heading, then at a presumed active point will instantly snap to an intercept point even if the target is outside of seeker constraints. This means that any defensive measures outside of kinematics are useless to defeat active homing missiles since they always remain passively aware of a target's position. This is easiest to observe with the AIM-54 missiles, but both the R-77 and AIM-120 have a higher probability of hit due to shorter engagement distances.

 

 

To test:

 

Select aircraft capable of employing active radar missiles (J-11, MiG-29S, F-15C, F/A-18C, F-14B), lock a target (TWS or STT), fire the appropriate missile (R-77, AIM-120B/C, AIM-54A/C), then break lock or turn cold. Missile will continue down the last guidance path, then at a set distance will go active and maneuver to intercept the previously designated target.

arh_aim120c_missile.trk

arh_r77a_missile.trk

arh_aim54c_missile.trk

[canadianbaken]

Pretty sure that’s how those missiles work. They don’t need guidance after being launched.

[NeedzWD40]

Pretty sure that’s how those missiles work. They don’t need guidance after being launched.

 

 

My understanding is that until the seeker is set to active and acquires a target, they rely upon the launching aircraft's data track for guidance. Thus the reason for the countdown timers with the F/A-18C and F-15C aircraft til missile goes active, or pitbull.

 

 

If the firing aircraft breaks lock, no more data is sent to the missile and it properly follows the last instructed course (and may or may not begin an active search pattern, but that is beyond my knowledge of the current missile systems). However, the problem is that they know instantly where the previously designated target currently is once they reach their active timer. It's easiest to test with the F/A-18C as it lacks TWS; in the AIM-120 demo mission, you can lock, shoot, break lock, and shoot until your missiles are expended and they will more often than not hit their targets (if launched with enough energy).

[Rabbisaur]

I’m pretty sure this is a well known issue.

 

ED needs to fix it.

[Ironhand]

Defined parameters in lua are:

Fi_start; // tracking and sighting angle at launch

Fi_rak; // allowable target angle

Fi_excort; // angle of tracking (sighting) of the target by the rocket.

Fi_search; // limit angle of free search

 

Aim120B parameters:

Fi_start = 0.5,

Fi_rak = 3.14152,

Fi_excort = 1.05,

Fi_search = 1.05,

 

....

 

Angles in radians.

 

...

So translating the values for the AIM-120B, for instance, you get:

 

Aim120B parameters:

Fi_start = 28.6°,

Fi_rak = 180°,

Fi_excort = 60°,

Fi_search = 60°,