Ballistic calculator

[Bestandskraft]

Would have posted this in the "DCS Wishlist" sub-forum, but the "new thread" button does not show up for me there.

 

On to business:

 

For attack planning, especially for some of the older modelled aircraft, it would be nice to have a ballistic calculator for at least all the unguided bombs available, either integrated into the game or as an external applet.

 

Although some real-world ballistic tables can be found on the internet, it is unclear whether the in-game weapons are coded to behave exactly as their real-world counterparts (probably not), so those tables are mostly useless.

 

Since ED knows which formulas they use to model weapon ballistics in the game, I imagine it would be relatively easy to make such a calculator available for the end user.

 

For those unfamiliar with ballistic tables/calculators:

 

The user enters data such as release velocity, dive angle, release altitude, stick size and bomb spacing, and the calculator determines e.g. bomb range, time of flight, impact angle, impact velocity, pattern length, and sight depression at release.

 

Any chance ED could provide us with such a tool?

[Captain Midnight]

There are things like this for artillery, sniping, and such. But when would you have time to do this in a fast bombing run? Probably why I've never seen one for aircraft in real life. The thing your looking for is the backup bombing sight. That thing that looks like a spiderweb on the hud. I hope to find some real life data charts for it on the internet one day. If you wanted to use a calculator, you would have to do this before the mission, at base, as your planning your attack. Then hope that you can get near that situation in the real battle (probably not). Too many nasty surprises always waiting to mess up your plans.

 

As for realistic values, I know they are constantly working on their missile FM. Not so sure about their 20,23, and 30mm shells, but they seem to be modeled well.

Edited October 17, 2015 by Captain Midnight

[Bestandskraft]

If you wanted to use a calculator, you would have to do this before the mission, at base, as your planning your attack.

As I stated in my OP ("attack planning"), this would be the purpose of the calculator I'm suggesting/requesting.

[dotChuckles]

There are things like this for artillery, sniping, and such. But when would you have time to do this in a fast bombing run? Probably why I've never seen one for aircraft in real life. The thing your looking for is the backup bombing sight. That thing that looks like a spiderweb on the hud. I hope to find some real life data charts for it on the internet one day. If you wanted to use a calculator, you would have to do this before the mission, at base, as your planning your attack. Then hope that you can get near that situation in the real battle (probably not). Too many nasty surprises always waiting to mess up your plans.

 

As for realistic values, I know they are constantly working on their missile FM. Not so sure about their 20,23, and 30mm shells, but they seem to be modeled well.

 

I suggest you start here http://forums.eagle.ru/showthread.php?t=99688 and also research what a z-sled diagram is. You will find them for many aircraft in real life ;-)

 

Your ideas about real world unguided munitions delivery are a little bit misinformed. Attack profiles are flown very accurately, and to plan in terms of dive angle, release point, minimum altitude and escape manoeuvre, even in CCIP modes, and are not just a "bombing run" done on the hoof. These attack profiles are known in advance and trained. Pilots don't just "put the thing on the thing" and squeeze the trigger. If flown correctly they should allow accurate delivery with the fixed net or depressible pipper sights in addition.

 

I suggest you watch the following video for an idea of how to achieve this level of realism in the sim. There are also some videos of this being taught in the real world in the T-38, but I can't recall the channel they were on.

 

To the OP, this will also go a long way to correctly answering your questions :-)

 

[Bestandskraft]

@dotChuckles:

 

Nice video, however it does not explain how you guys obtained the BDU-33 bomb range upon which your z-sleds are based. Also I could not spot a sight setting in your video (resolution is not the best though). Based on what I know about the 476th I would assume you have access to CWDS and/or the -34 tables, however this is not particularly helpful in this context since

 

a) we do not know whether the in-game ballistics are identical to real-world ballistics, and

b) comprehensive data for Russian/Eastern bombs do not seem to be available online, and

c) the sight setting would differ for each aircraft due to different angles of attack/incidence at release parameters.

 

If you could verify that using the real-world data has been successful for you that would solve point a) [at least for those who have access to the relevant material], but not points b) and c).

[dotChuckles]

Hi Bestandskraft, I am not in the 476th or responsible for developing any of this useful stuff. I was more trying to disabuse CaptainMidnight of his view that unguided weapons delivery was merely a "high speed bombing run" done off the cuff due to "nasty surprises".

 

My understanding is that this data was gather using a tool that they wrote called DAPS (Digital Attack Planner) which is not publicly available. You would need to join their excellent squadron to get access to it. If you read through the thread that I posted there are some good examples in it of how to utilise the tables.

 

Ultimately though you do not require to adjust the sight. If your speed, altitude ATL and dive angle are correct (all of these things will mean that your AoA is a known quantity) for the calculated delivery, your bombs will hit if the depressible pipper is over the target or not. It is merely a reference to check you've got your flying right.

 

What you are referring to is something called the "bombing triangle" http://navyflightmanuals.tpub.com/P-1219/P-12190044.htm (you can navigate through that document by clicking the page numbers in the top right)

 

As I only ever drop Mk82's the battle book works for me. I understand that there is data available for Russian munitions but sadly I do not speak Russian so haven't spent much time searching.

 

So in short... a) correct b)sadly correct c) refer to the manual I linked in order to begin to understand how to work it out. Maybe some testing of Russian munitions might be a good project to gather data! I understand that's how the 476th got their numbers for the munitions, but I could be wrong.

[Captain Midnight]

The best laid schemes of mice and men... :p

[Bestandskraft]

Hi Bestandskraft, I am not in the 476th or responsible for developing any of this useful stuff.

My apologies.

 

My understanding is that this data was gather using a tool that they wrote called DAPS (Digital Attack Planner) which is not publicly available. You would need to join their excellent squadron to get access to it. If you read through the thread that I posted there are some good examples in it of how to utilise the tables.

I have actually had their Battle Book for a while, not realizing there was an associated thread. From reading it it seems the 476th are either using RL (Western) data/bomb ranges (which probably means those are quite close to the in-game values), or they have derived the data from in-game testing. I was hoping to avoid the latter, hence my request for a calculator released by ED. Just to be clear: I already know how to calculate a z-sled in principle, I only lack empirical data (mostly in-game bomb ranges and TOFs for different release parameters) to feed my formulas. Just using the 476th z-sleds is not an option since at the moment I'm flying the MiG-21 whose tactical flight envelope is just too different.

 

Ultimately though you do not require to adjust the sight. If your speed, altitude ATL and dive angle are correct (all of these things will mean that your AoA is a known quantity) for the calculated delivery, your bombs will hit if the depressible pipper is over the target or not. It is merely a reference to check you've got your flying right.

You are of course correct. Assuming you are on parameters and use your altimeter to determine when to pickle, you will hit even without the sight. Its main purpose then would be lateral alignment and the avoidance of altimeter lag (which is, I believe, not simulated in DCS).

Edited October 20, 2015 by Bestandskraft
Typo

[Bestandskraft]

With the AJS-37 released, having an official in-game value based bomb range etc. calculator seems more useful than ever.

 

Any chance of getting one?

[gospadin]

Pre-calculated ballistic tables for weapon delivery existed for many aircraft up until the late '60s or early 70s.

 

Cross reference your airspeed and altitude and it tells you a gunsight depression value to use for the weapon you're using.

 

These then drive the mission profile planning, e.g. "approach target on a heading of 120° at 1250' MSL at 400 knots and set your gunsight for 122 mils".

 

The trick is that these documents were typically part of tactical manuals which are classified, very few are available on google.

[Bogey Jammer]

I think it's possible to at least recreate the tables based on measurements with the help of Tacview, but I'm currently too lazy to do it…