Grid, True, Magnetic Norths, Meridians and DCS

[Robin_Hood]

Hi all, I know this has been more or less discussed several times, but I'm not sure there have been definitive answer, so I'd like to know your thoughts about this.

 

Note: I am using the Mirage 2000C to get bearings, so if you think it is an implementation problem within that module, I'll report it, but I think the problem is deeper Inside DCS World.

 

Here's the thing, plain and simple:

 

Flying north along a constant longitude line. Here are the headings I get from various sources.

 

HDG Mag (M-2000C): 346° (approx)

HDG True (M-2000C): 352.6°*

HDG F10 map: 352 (approx)

 

* From the INS reading

 

Magnetic Variation is 6.1.

Since 346° + 6.1° = 352.1°, this sounds alright (Mag + Var = True).

 

However, the meridian is clearly not pointing to the true North there. In fact there is, at that location (somewhere South of Gori) a 80 difference between "F10 North" (as implied by the game) and "Meridian North" (as implied by the meridians on the map - and indeed the coordinates).

 

Could it be that the F10 map actually shows Grid North (which would sound logical), and that the module(s) incorrectly use that as True North and to derive magnetic headings ?

 

Also, as the coordinates indeed agree with meridians, might that not cause trouble in some places* ?

 

* I have already noticed that if you want to deduce coordinates from a starting point and bearing + distance, you should add the F10 North-to-Meridian North difference to gain a good order of accuracy.

 

Also, let me know if I wasn't clear.

 

EDIT: I have just come across this post that states that, indeed, Grid North (F10 North) is used in place of true north by aircraft modules (eg, magnetic headings are calculated via Grid North).

Edited October 29, 2016 by Robin_Hood

[NeilWillis]

That surely is the most logical conclusion, and in mapping terms, why would you ever need to use true North? Grid and mag are the only two I ever used in map reading.

[GUMAR]

The Earth in DCS is flat. So it has the same drawbacks as a common paper map has.

[Weta43]

Apparently, 2.0 on supports spherical mapping (though not used yet as all maps in development were started before the feature was added), so maybe in the future maps won't have that problem...

[Robin_Hood]

The Earth in DCS is flat. So it has the same drawbacks as a common paper map has.

 

Sure, but actually no. It works different from a paper map. Grid North is used in place of True North pretty much everywhere but for coordinates.

 

 

Apparently, 2.0 on supports spherical mapping (though not used yet as all maps in development were started before the feature was added), so maybe in the future maps won't have that problem...

 

Thanks, good to know. Well, I guess this will stay a peculiarity we'll have to live with for some time, then. It can be quite puzzling when you come across it.