Question about CCIP

[vparez]

As far as I understand we have 3 options of CCIP bomb delivery:

 

1. Using ballistic computer which doesn't know what is the true ground height at the impact point, nor what is the above ground altitude of the plane;

 

2. Using 1 + RS; knowing the true vertical distance to the ground below the plane by radar altimeter then assuming the ground is the same level at the impact point;

 

3. using 1 + TAS; radar to directly measure the slant range to the impact point.

 

If the above is correct, and since we don't designate the target in CCIP, how is then the slant range measured in TAS mode? How does the radar know where to look? Does it look automatically at the initial pipper solution by the ballistic computer and then projects a true impact point on the HUD? And what happens if the initial CCIP solution is below the radar elevation gimbal limits? There is no visual cue for this?

 

And, if the plane is above a mountain at the moment of release (all around it is flat ground) and the target is on flat ground, does it mean that using the RS mode will induce a bigger error than if only the ballistic computer was used?

Edited October 2, 2016 by vparez

[Frederf]

The ballistic computation is always in effect in any mode. The question is where does it get its height above target plane value from.

 

Radar knows where it's putting the pipper on the HUD so it looks along that vector. It's an iterative process which quickly converges. The radar probably doesn't attempt to measure distance too far beyond the HUD pipper limits and certainly not beyond the radar limits. Since the HUD pipper limits are always within the radar elevation and traverse limits there should never be a need to have an indication for no solution as it would be off the HUD anyway.

 

In cases where the height source is unavailable it should use the next source in the priority list. If the fallback sources are all unavailable presumably no solution is calculated or shown.

 

Yes if slant range calculation by height is given a non-representative height then the solution will be wrong in turn. If the radar is unavailable and RS appears to not be a good method due to terrain then another method should be used. The Mirage uses some method to continue the ballistic calculation even if neither RS nor TAS are selected. It should probably be INS-based (ownship delta to currently selected waypoint) or possibly barometry (unlikely).

[vparez]

Thanks for the reply!

 

Hmmmm, yeah good point about deltaH vs a waypoint; when I think about it, there is most likely a waypoint relatively near to the intended target which can be used to provide the H.