world coordinates to GAUSS KRUEGER

[Unbekannt]

Hello everbody,

I have a lot of location points, collected with GPS in world coordintes.
My mapes here in Germany are in GAUSS KRUEGER coordinates. This causes me
a lot of trouble.

Therefore I am asking you if anybody has a program or knows where to get one
for converting world coordinates into GAUSS KRUEGER format!

Thanx a lot in advance!

Karl

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Karl Wild t96...@sun1.lrz-muenchen.de
phone +49-8161-713884 or ka...@tec.agrar.tu-muenchen.dbp.de
fax +49-8161-714048
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[Ferenc Csillag]

On Karl Wild's question:
During the last 47 years the Gauss-Kruger projection has been quite popular
East of the Elba River. In fact ALL military maps...
So try with them first.
I'd guess that all geodesy/cartography books published in that period
would also give you a formula.

*Ferko Csillag
Geography / Syracuse

[Ari T Jolma]

Here is an algorithm to convert latitude & longitude (world
coordinates?) i.e. (lambda,phi) into Gauss-Krueger -coordinates
centered around some meridian (G-K centered to 27.0 are called
common coordinates or "artillery coordinates" in Finland, that
is set as Const into the code).

The code is Turbo Pascal and is an member function to class
LatLongCts, which is simply a record of x,y:Double. CommonCts
has same data as LatLongCts (is also a descendentant of the
DoublePoint). The result is in kilometers (XY.y is easting
from Merid and XY.x is northing from equator). The rest should
be clear from the code.

Ari Jolma (ajo...@hila.hut.fi)

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The code starts from here:
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Procedure LatLongCts.ConvertToCommonCts(Var XY:CommonCts);
(* Reference: Hirvonen 1972, Matemaattinen geodesia, TKY 305, Otaniemi p.31,67
original fortran algorithm by Y.Rauste 1985 *)
Type Array1_4OfDouble=Array [1..4] of Double;
Const Merid=27.0;
b:Array1_4OfDouble=(6367.65450006,-16.10703468,0.01697621,-0.00002227);
c=26399.93660810;
ep2=0.6768170197224E-2;
epsil=1.0E-12;
Var phi,lambda,vd,vd1,temp,phid,xp:Double;
EndLoop:Boolean;
i:Integer;
Begin
lambda:=Degr2Rad(y);
lambda:=lambda-Degr2Rad(Merid);
phi:=Degr2Rad(x);
vd1:=Sqrt(1+ep2*Sqr(Cos(phi)));
i:=1;EndLoop:=False;
While (i<1000) and not EndLoop do
begin
phid:=ArcTan(Tan(phi)/Cos(vd1*lambda));
vd:=Sqrt(1+ep2*Sqr(Cos(phid)));
EndLoop:=Abs(vd-vd1) <= epsil;
If not EndLoop then
begin
vd1:=vd;
Inc(i);
end;
end;
temp:=Tan(lambda)/vd*Cos(phid);
XY.y:=c*Log(temp+Sqrt(Sqr(temp)+1))+500;
XY.x:=b[1]*phid+b[2]*Sin(2*phid)+b[3]*Sin(4*phid)+b[4]*Sin(6*phid);
End;
Ari Jolma *
tel. 451 3831 *
ajo...@hila.hut.fi *
Building W, HUT, 02150 Espoo, Finland *