CCRP and CCIP Calculations

[Lt_Maverick]

In an A10C, what systems input an what calculations are used to render the impact point on the HUD. I.e. What is the algorithm and what systems produce the data?

[Flagrum]

http://forums.eagle.ru/showthread.php?t=141171

(no real answer, but I'd like to know more about it, too.)

[Zabuzard]

As I took part in modding a CCIP solution for ArmA 3, here's the physics behind:

 

https://en.wikipedia.org/wiki/Projectile_motion

 

There are many applications like games that need to calculate such motion. For example a golf game or shooter games etc. Because of that the topic is well documented.

 

For example here is the description of an iterated program calculating the impact point of a golf ball:

http://ualr.edu/dcwold/phys2321/golf/golf.html

 

As you see, really important are:

- Speed in x and y (Speed Vector)

- Gravity (+ G-load)

- Constant weapon data like airfriction, acceleration (rockets) etc.

Edited March 13, 2016 by Zabuza

[Flagrum]

A paper I found quite interesting:

http://msemac.redwoods.edu/~darnold/math55/deproj/sp09/wilsonpepper/cpandcwfinal.pdf

 

I started to make an excel sheet based on this ... but as a math noob, it turns out to be ... challenging. Right now, I think, I am "just" missing the drag factor of the ordnance - missing in the sense so that it fits into the forumlas I derived from the paper...

[Zabuzard]

Nice paper! Can you derive a very coarse estimated value for the drag (value k in the paper), based on your calculations?

[Flagrum]

Nice paper! Can you derive a very coarse estimated value for the drag (value k in the paper), based on your calculations?

My graphs look similar to what is shown in the paper ... but that's it. The word "coarse estimation" is atm a too big word to use for that - it is probably more like "yeah, seems I am on the right hemisphere" :o)

 

But when I find the time, I might work on that more. Perhaps just by adjusting k to match the results to what can be seen in DCS ...

 

Btw, what is missing in that paper altogether are the effects of temperature and altitude - or better, the change of air density and thus the change of drag the projectile experiences when traveling through the air. Not sure how much of an impact that possibly can have ... but if we want to hit tanks with dumb bombs, every meter counts, I suppose ...

Edited March 13, 2016 by Flagrum

[Puma]

Dont forget wind and terrain data.

[Lt_Maverick]

Thanks for all the heads up guys. I'm trying to figure out where all of the data is absorbed and which system makes the calculation.

[Puma]

I beleive the cicu would be considered the meeting point. It consumes data from many sources as listed above so it would have to be something quite central.

[Zabuzard]

You can deliver guided ammunition with "CICU Fail" (which commonly happens due to combat damage). Doesn't that conflict with CICU being the source? Or maybe the A-10 then uses other backup sources.

[Puma]

Nope, i interpret that to mean something else does it. Good point.