[comp.binaries.ibm.pc.d] Microsoft Flight sim and lat/long coords

kemp@convex.com (Phil Kemp) (06/11/91)

Does anyone know how to convert a latitude and longitude designation
to the internal coordiantes for the M/S flight sim 4.0... I have the
base coord of 0 x 0y ( Champaign, Ill . ) but I have no idea how the
increment works.

BTW is there a central depository of PD Scenery files anywhere on the
internet or bbs'

Thanks
PK

--
Phil Kemp
CONVEX Computer of Canada Ltd.
Voice:(403)-233-2815
UUCP:kemp@convex.com

jcwasik@PacBell.COM (Joe Wasik) (06/12/91)

In article kemp@convex.com (Phil Kemp) writes:
>Does anyone know how to convert a latitude and longitude designation
>to the internal coordiantes for the M/S flight sim 4.0...

Excellent question.  Someone please answer.

>BTW is there a central depository of PD Scenery files anywhere on the
>internet or bbs'

There is an FSFORUM on CompuServe.  They have a number of sceneries that
people share.  Nothing high-quality though.


-- 
Joe Wasik, Pac*Bell, 2600 Camino Ramon, Rm 4E750V, San Ramon, CA (415)823-2422
email: jcwasik@clib.PacBell.COM or [...]!pacbell!clib!jcwasik

adf@crosfield.co.uk (alex france) (06/13/91)

In article <9013@pbhyf.PacBell.COM> jcwasik@PacBell.COM (Joe Wasik) writes:
>In article kemp@convex.com (Phil Kemp) writes:
>>Does anyone know how to convert a latitude and longitude designation
>>to the internal coordiantes for the M/S flight sim 4.0...
>
>Excellent question.  Someone please answer.

Yes, I couldn't agree more. I've recently been playing with the
scenery editor adding my local field correctly and local visual
reporting points. I started from SubLogic's Western Europe scenery
disk which has the runways wrong for my local field (Cranfield) and
doesn't have the VOR on the field, etc.

Now, when I slew to the field the Latitude comes out OK (i.e the North
bit), but the longitude is wrong by a few degrees. I put this down to
the 'grid canted by -8 degrees to map onto Lambert Conformal Conic'
comment.

So, I stuck to putting in the scenery in MS co-ords relative to where
it thought my local field was. As far as I can work out,

	0.0001 MS Co-ord units ==> 1 inch

	(which gives 6.336 ==> 1 st mile, 7.2 ==> 1 nt mile)

These seem to work out about right for objects within 5 to 10 miles
from a known reference, but I could really do with the maths to
convert Long/Lat direct into the co-ords for further afield stuff.
Anyone know?

Alex France, Crosfield Electronics, | Phone: +44 442 230000 xt.3541
Hemel Hempstead, HP2 7RH, England.  | Fax:   +44 442 232301
adf@crosfield.co.uk or mcsun!cel!adf@uunet.uu.net

martin@cat.de (Thomas Martin) (06/20/91)

>Does anyone know how to convert a latitude and longitude designation
>to the internal coordiantes for the M/S flight sim 4.0... I have the
>base coord of 0 x 0y ( Champaign, Ill . ) but I have no idea how the
>increment works.

Hi Phil!

In an old Computer magazine I found a formula to convert the FSIII coordinates
to the common longitude/latitude values:

Note that the East coordinates depend on the scenery used and that the North
coordinates refer to the west of Greenwich.

N=(B*17586/49.5)

E(european scenery)=(52.31965 - L) * 263.60656

E(american scenery)=(135.366 - L) * 340.625

B: Latitude in degree
L: Longitude west of Greenwich (Longitude values east of Greenwich have to be
   entered as negative values) e.g. 11.7 degree east= -11.7 degree

N: North coordinate of FSIII
E: East coordinate of FSIII

I tried these formulas with FSIV. It works fine with the old european scenery
from FSIII which I use with FSIV but unfortunately it seems as if Microsoft
has changed the internal coordinate system in FSIV because the positionning
in the american (FSIV) scenery is not as exactly as in the european one.

Nevertheless, I hope that helps somehow.

Regards,

Thomas Martin

---
  Thomas Martin (martin@cat.de)                     
  C.A.T. Kommunikations-System, Frankfurt, Germany

sietec@infohh.rmi.de (Sietec Consulting) (06/23/91)

In <kemp.676618862@convex.convex.com> kemp@convex.com (Phil Kemp) writes:

>Does anyone know how to convert a latitude and longitude designation
>to the internal coordiantes for the M/S flight sim 4.0... I have the
>base coord of 0 x 0y ( Champaign, Ill . ) but I have no idea how the
>increment works.

>BTW is there a central depository of PD Scenery files anywhere on the
>internet or bbs'

>Thanks
>PK

>--
Well, at least for the West European Scenery region around
Germany I found the following relations:
NORTH = 416.0 x LAT - 3007
EAST  = 278.2 x LONG + 13617
where LAT,LONG are latitude and longitude expressed in degrees
(and fractions of).
Note that one coordinate unit in FSIV corresponds to 260 meters
and the above relations are good enough to give results within
1 kilometer.

BTW, I made a complete scenery of the Frankfurt/Germany region,
including details of FRA airport, all smaller airfields and 
quite a number of environmental details.

Hope, this information was useful.
Ralf Wiegandt
(Internet: sietec@infohh.rmi.de)