CCIP and TAS ... how does it work?

[Flagrum]

To get a valid bomb release solution, the aircraft needs to know the exact position of the intended target. Important here is especially the target elevation.

 

The necessary parameters are: height over ground of the aircraft, elevation of the target, aircraft speed and the bomb trajectory formula. We get an approximation of the TGT elev. if we use the radar altimeter if the terrain is flat (i.e. our height above ground is the same at release point as it would be over the target). But when using radar slant range measuring (TAS mode), we get (or are supposed to get, once it is fully implemented) the exact TGT elevation - thanks to pythargoras.

 

So far, so good. But in CCIP we don't even know where the target is. So which slant angle does TAS use to measure the range, how does the radar know where to look at? At the computed impact point? Well, we don't know that either, yet, as we are just about to compute it ... right!?

 

So, what is it, probably quite obvious in my lacking math and physics knowledge, that I am missing here? :o)

[TomCatMucDe]

I think because the beam mode is actually a vertical radar line. So you know the distance of every point right in front of you. Knowing your speed, the computer can permanently calculate the impact point.

[Flagrum]

Good point. That could probably also explain, why TAS is still WIP if this would require some sort of radar ground mapping functionality.

[PiedDroit]

It's probably an iterative process. SU-25T has the same issue with its laser ranging.

[Azrayen]

But in CCIP we don't even know where the target is. So which slant angle does TAS use to measure the range, how does the radar know where to look at? At the computed impact point? Well, we don't know that either, yet, as we are just about to compute it ... right!?

 

So, what is it, probably quite obvious in my lacking math and physics knowledge, that I am missing here? :o)

 

I suggest a fixed reticle (at the ground-end of a fixed beam) that the pilot makes co-incide with the intended target, before pressing the "designate" button; radar then measures slant range, makes its calculations, and the system displays (or update?) the CCIP piper. All very quickly of course, thanks to the computerization. :)

[Flagrum]

I suggest a fixed reticle (at the ground-end of a fixed beam) that the pilot makes co-incide with the intended target, before pressing the "designate" button; radar then measures slant range, makes its calculations, and the system displays (or update?) the CCIP piper. All very quickly of course, thanks to the computerization. :)

But that could/would cause the pipper to jump ... right when the pilot has "put the thing on the thing", it suddenly jumps further out/upwards, or worse, jumps closer/downwards.

[jojo]

No, I don't think so. It wouldn't work for rocket and AG gun.

 

Depending on flight parameters the plane knows the weapon ballistic trajectory.

So I think the antenna is pointed to have a ground return at a range that match the weapon's ballistic trajectory.

[Azrayen]

Flagrum: See a better way? The beam would be set to minimize/nullify the "jump" with standard attack profile.

 

jojo: Yes of course, fixed beam elevation should depend on weapon type/ballistics.

[Flagrum]

Flagrum: See a better way? The beam would be set to minimize/nullify the "jump" with standard attack profile.

 

jojo: Yes of course, fixed beam elevation should depend on weapon type/ballistics.

No, I do not - that's why I started this thread :o)

 

But what TomCat suggests (or how I understood it) makes some sense: if the radra beam scans back and forth where the bomb trajectory most likely will intersect the terrain ... like scanning along the bomb trajectory to determine where it actually will meet a point where the radar gets the first terrain reflections that is in the same distance as the calculated bomb trajectory.

 

Or to put it differently: scanning the terrain to generate a elevation map of a strip of ground along the flight path which the computer then uses to calculate the impact point.