Coordinates in Falcon
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I have a question:
I am working on a small app for BMS and found out that the geographical coordinates of RW do not match the Falcon coordinates. It is not much….
Example for VORTAC Kunsan
Real:
N35°54’37’’
E126°36’41’Falcon (according to Korean Volume BMS doc)
N35°58.39’
E127°25.38’I am pretty sure that this was discussed before etc, but can´t find it anymore.
What is the reason for that? Is that because the earth is flat in Falcon? Because if it is, then I can transform the real coordinates for Falcon.
Thanks for any help.
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It is a projection issue: indded, in Falcon, the earth is flat.
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rgr……then a transformation will solve my problem.
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rgr……then a transformation will solve my problem.
Are you reading these coords out of Falcon somehow?
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Hi tbuc maybe you can contact uri_ba.
He wrote DTC Converter to transform coordinates from Falcon to RW as I understand things.
So your solution seems to be f=(DTC Converter0.1)-1 -
Are you reading these coords out of Falcon somehow?
I was reading the local position via the mapped memory and trying to transform to coordinates. And vice-versa from outside.
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Hi tbuc maybe you can contact uri_ba.
He wrote DTC Converter to transform coordinates from Falcon to RW as I understand things.
So your solution seems to be f=(DTC Converter0.1)-1Uri did not reply my emails in the last months …may be I have the wrong one. I figured out this afternoon on how to do what I want. Thanks anyway!
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Uri did not reply my emails in the last months …may be I have the wrong one. I figured out this afternoon on how to do what I want. Thanks anyway!
Do you have a formula for converting the memory mapped coordinates to Longitude Latitude?
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I don´t have right here, but if you are interested I can get it. For which theater you want?
What is that for? If am I not wrong, you were trying to drop bombs in Falcon and hit tgts in Arma, correct?
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Don’t know if useful, but I found this thread
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For Korea:
North Coordinate=121842.01661 + 0.00985*NorthFeet
East Coordinate = 443294.76742 + 0.01187*EastFeet
Coordinates are in seconds…you still have to convert to degrees, minutes, seconds.
NorthFeet and EastFeet are the values read via memory map.Hope it helps you in your Arma project.
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Don’t know if useful, but I found this thread
That would also work out. Did something more brute force since I did not know the origin Falcon coordinates.
EDIT
Although I had obtained the formula above by simply fitting of the coordinates versus memory positions of 10+ airbases spread over the Korea Peninsula (between Shenyang and Kadena), I just read the post of Steveh112 and the formula I gave DOES not work for the NE….curvature of the earth. I did not test his method, but looking quickly it seems correct. I was naive thinking that because Korea covers a small range of latitudes/longitudes, a linear fitting would work out. Wrong. Even for such small theather you need to take into account the earth curvature or you will get some degrees of error.
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Hmmmm, that topic link s helpful. And yes you are correct about what we are doing except for the trying part - we are able to drop bombs in Falcon and have them land and even be guided in Arms 3. The thing is, our system is using and displaying coordinates right now, and we would like to have it display longitude/lattitude to help talk pilots onto a target.
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EDIT
Although I had obtained the formula above by simply fitting of the coordinates versus memory positions of 10+ airbases spread over the Korea Peninsula (between Shenyang and Kadena), I just read the post of Steveh112 and the formula I gave DOES not work for the NE….curvature of the earth. I did not test his method, but looking quickly it seems correct. I was naive thinking that because Korea covers a small range of latitudes/longitudes, a linear fitting would work out. Wrong. Even for such small theather you need to take into account the earth curvature or you will get some degrees of error.
Per this:
https://www.benchmarksims.org/forum/showthread.php?10420-about-GPS-coordinates&highlight=curvature
Falcon maps apparently don’t model curvature, so something else might be off with formula?
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Per this:
https://www.benchmarksims.org/forum/showthread.php?10420-about-GPS-coordinates&highlight=curvature
Falcon maps apparently don’t model curvature, so something else might be off with formula?
I think we should distinguish two things:
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x,y from memory map compared to coordinates obtained from the recon in the UI or cockpit. The post of steveh112 seems to be correct.
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Coordinates obtained from the recon in the UI or cockpit compared to reall world coordinates. Projection of the korea map seems to be distorted! Maybe an inteporlation/fitting could give you an expression to relate them.
Do you need to compare falcon to real word coordinates for your Arma app?
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I think we should distinguish two things:
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x,y from memory map compared to coordinates obtained from the recon in the UI or cockpit. The post of steveh112 seems to be correct.
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Coordinates obtained from the recon in the UI or cockpit compared to reall world coordinates. Projection of the korea map seems to be distorted! Maybe an inteporlation/fitting could give you an expression to relate them.
Do you need to compare falcon to real word coordinates for your Arma app?
No, I need them relative to the ARMA coordinates. But I was just pointing it out because I thought it might be relevant to your issues. I have no idea if it will (or is?) affect me or not.
Mostly I need to be able to translate ARMA coordinates back into something the F-16 pilot can understand, so they could (for example) manually enter a steer point for a bomb drop. I would MUCH rather hack into Falcon so it could display the MARK POINT DATA RECEIVED message in the HUD but I am not sure about the feasibility of that (Thoughts, Devs? If any of you are reading?). I am reasonably certain DATA LINK functionality was added in BMS, so looking at the FF source code as I have been (to get as far as I have) would not be possible to implement that.
Realistically, we almost NEVER use the script without a laser designation on the ground (which feels so much like cheating it isn’t even funny) so I don’t know how much this would really get used, but I am going to do it anyway.
At any rate, I already have what I need to move Coordinates (X/Y) between the two systems I am just looking for something a little more polished to display to all the end users that they can help to create situation awareness.
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I dropped my initial idea of trying to find real coordinates in Falcon. I would need first to translate the real coordinates to Falcon coordinates, then translate the x,y from the memory map. Toooo much trouble. Since for my app I just need a reference point close to a given airport, I decided to make all calculations relative to the runway threshold being used. Angles and feet. This part is done. I am now writing a state machine and doing some debug.
In your case, I am thinking, you may face some isues. When I wrote “real world coordinates”, you can read “Arma coordinates” or any external coordinate system. What you could try do that is:
- Get the real coordinates of 20+ airbases spread nicely over the Korea peninsula. AIS of South Korea is the place to go. And Goodle maps, of course. Try to get the coordinates of the runway threshold, since that is easier to read later in Falcon.
- Get the coordinates of the same 20+ airbases in Falcon, runway threshold.
- Now try to fit all these points with a function that depends on the lat and long.
It is doable, but takes sometime to write that. At the end you would get a function with an imput of external coordinates that would give you the Falcon coordinates.
Regarding the input of coordinates (or any kind of data) into the 3D world (MFD, DED, etc), I can tell you I tried many times to hack the MP traffic between server and host to do that, as well as the Falcon memory, without much success. The only thing I managed to do was to change the fuel as well as aerodynamics coefficients of airplanes flying by humans in the 3D world in real time. That could be a nice application for flight model testing/development, etc though. If you managed to insert data in Falcon…that would open thousands of applications…Simulation of Datalink16 with an external AWACS/JSTAR, simulation of soviet way of GCI, simulation of real EW, etc. If you know how to do that, please let me know.
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Regarding the input of coordinates (or any kind of data) into the 3D world (MFD, DED, etc), I can tell you I tried many times to hack the MP traffic between server and host to do that, as well as the Falcon memory, without much success. The only thing I managed to do was to change the fuel as well as aerodynamics coefficients of airplanes flying by humans in the 3D world in real time. That could be a nice application for flight model testing/development, etc though. If you managed to insert data in Falcon…that would open thousands of applications…Simulation of Datalink16 with an external AWACS/JSTAR, simulation of soviet way of GCI, simulation of real EW, etc. If you know how to do that, please let me know.
I have hacked a single coordinate (y) in a single steerpoint…and changed it from outside of Falcon, yes. As for how I do that, well let me make sure I can do it reliably to an entire steerpoint and then we can talk about it. (I will share the code, I always do, the code for what I have done so far is on Github, minus this piece).
But all I am doing is hacking a memory value. It’s not the eye opener you might think it is.