How aircraft calculates CCIP

[uhntissbaby111]

This is just a question for my general curiosity. How is the impact point calculated? The aircraft knows all of its information ie speed and altitude. But I’m assumimh it also needs the distance to impact point, where the reticle is pointed. I guess it could use math. If it knows altitude and distance over ground, it can solve for slant range? Or is there a sensor that ranges the distance, like a range finder?

[The Integrator]

The A-10 gets the target elevation from the DTS elevation map. From the A-10 FAQ:

In order for the IFFCC to compute a CCIP solution, it must know the elevation under the CCIP pipper (gun, rocket, bomb, etc.). This can either be a HOT elevation based on the Steerpoint elevation, or DTS elevation stored in the digital map database system. If not in DTS and the steerpoint is at a higher elevation than the CCIP pipper, you will get a CCIP INVALID message. Unless you have a DTS failure, you should always use DTS, as indicated on the HUD in the data block. If you do not see DTS, press the DATA rocker on the UFC and then the SEL rocker until DTS appears.

You can also input it manually (as a HOT elevation mentioned above). I guess the F/A-18 is the same.

[jojo]

Guys, CCIP existed long before DTED was even imaginable...

No DTED when F/A-18A has been put into service.

 

The plane compute the ballistic solution, and yes the radar is used to find a slant range which match the bomb fall trajectory and display the point in the HUD.

 

DTED is a work around for planes without FCR like A-10.

[jojo]

It depends if we are talking about the real thing or the simulator.

Simulators can cheat in a lot of way, I think trying to stick real life technology name to these cheats can be confusing...

[IvanK]

IRL (no GPS,DTED,FLIR etc) CCIP ranging is calculated using an ordered method AGR, Radalt or Baralt. AGR is straight forward the radar range sample is used. If AGR is not available the the MC will try Radalt or Baro ranging using input altitude and known dive angle.... obviously not as accurate as AGR.

 

 

To command AGR you must have the TDC assigned to the HUD (dot in the vv)

[IvanK]

AAn old VFA125 FA18 Pilot training manual describing how ranging reversion is done FA18A. Obviously before GPS DTEM etc.

 

 

[QuiGon]

And then there are other systems like the Angle Rate Bombing System (ARBS), for radar-less aircraft like the Harrier or the Skyhawk, which meassures range based on the angular rotation of LOS to the target:

 

https://forums.eagle.ru/showthread.php?t=196709

 

 

The most simple way to get a CCIP solution is to just enter the barometric altitude of the target and use math to calculate a solution. The Viggen relies very heavily on this method for example. The problem is, that you need to know the altitude of the target beforehand.

[toilet2000]

And then there are other systems like the Angle Rate Bombing System (ARBS), for radar-less aircraft like the Harrier or the Skyhawk, which meassures range based on the angular rotation of LOS to the target:

 

https://forums.eagle.ru/showthread.php?t=196709

 

 

The most simple way to get a CCIP solution is to just enter the barometric altitude of the target and use math to calculate a solution. The Viggen relies very heavily on this method for example. The problem is, that you need to know the altitude of the target beforehand.

 

The Viggen can (and should in any normal situation when using a compatible delivery mode) use AGR-esque ranging. The fin appearing on the HUD indicates slant range calculation. This aleviates the need for accurate target baro altitude. In fact, you don’t need any more target info. You know the slant range (hyp of the triangle), you know your dive angle, you can compute accurate elevation info with that.

 

I’m almost certain the FA-18C uses the same kind of processing. If AGR is not available, it falls back to a balt/ralt altitude assumption. If so, you can manually designate a target point, either from waypoint (coordinates and elevation data of the waypoint entered) or from any other sensor (ATFLIR for example). CCIP computation will then be based on the elevation.

 

This last method is currently not functional in DCS, as designating a target makes CCIP mode automaically change to AUTO. It should not though.

[QuiGon]

The Viggen can (and should in any normal situation when using a compatible delivery mode) use AGR-esque ranging. The fin appearing on the HUD indicates slant range calculation. This aleviates the need for accurate target baro altitude. In fact, you don’t need any more target info. You know the slant range (hyp of the triangle), you know your dive angle, you can compute accurate elevation info with that.

This is true, but unlike other aircraft the Viggen uses radar ranging only at the very last moment to verfiy the exact target parameters. Up untill this point it relies on baro alt to show correct guidance on the HUD for the run in.

[Dangerman]

some more info here for you

 

https://forums.eagle.ru/showthread.php?t=199100

 

Height sensor if some sort BARO/ INS /Radalt (flat terrain).AGR or laser ranging(best of all!)is essential to have the pipper indicate something that equates to bomb parameters for your stage of flight.

 

A target of opportunity or true CCIP attack doesn't need target height entered...the system uses local parameters as described above. the target mark where th nav computer thinks it is needs a waypoint height to show you a ground stabilised marker.

 

A CCRP attack or a waypoint/target mark in HUD will use the target height set against the waypoint to ensure the diamond/TD box etc is shown ground stabilised at the correct point (with good integrity integrity of nav kit ) even slewing the mark will need an accurate height sensor if it is using the waypoint height against the waypoint since calculations are derived from this until an update to target relative height...... forward firing height sensor is the best .... its trigonometry done by a weapon computer.