RD-coordinates to WGS84

Does anyone have a script to convert RD-coordinates (Rijksdriehoekstelsel, applied in The Netherlands) to WGS84? Thanks, Marijn

Answer 1

[Marijn]

Hi Roland,

My professor has given me this script, also available through modflow, so I think it should be no problem to upload it here.

Good luck. Cheers, Marijn

function [lamwgs,phiwgs,LL]=rd2wgs(x,y)

% RD2WGS: Converts Dutch rd-coordinates to GE wgs lat(Easting) long(Northing) coordinates % % USAGE: % [long,lat,LL]=rd2wgs(x,y) % % fortran 90 routine received from Peter Vermeulen % converted to Matlab by TO 090916 % % SEE ALSO: wgs2rd, kmlpath kmlpath2rd getDinoXSec % % TO 090916

if nargin<2, [lamwgs,phiwgs,LL]=selftest; return end

[phibes, lambes]=rd2bessel(x, y); [phiwgs, lamwgs]=bessel2wgs84(phibes,lambes);

N=length(x(:)); LL=cell(N,1); % allocate for i=1:length(phibes(:)) LL{i,1}=sprintf('N %.7g, E %.7g',phiwgs(i),lamwgs(i)); end

function [phi,lambda]=rd2bessel(x,y) %convert xy to Bessel

x0 = 1.55e5; y0 = 4.63e5; k=.9999079; bigr = 6382644.571; m = .003773953832; n = 1.00047585668; e = .08169683122;

lambda0 = pi * .029931327161111111; b0 = pi * .28956165138333334;

d__1 = x - x0; d__2 = y - y0;

r = sqrt(d__1 .* d__1 + d__2 .* d__2);

warning off sa = (x - x0) ./ r; ca = (y - y0) ./ r; warning on sa(r==0)=0.0; ca(r==0)=0.0;

psi = atan2(r, k * 2. * bigr) * 2.;

cpsi = cos(psi); spsi = sin(psi);

sb = ca * cos(b0) .* spsi + sin(b0) * cpsi; d__1 = sb; cb = sqrt(1. - d__1 .* d__1); b = acos(cb); sdl = sa .* spsi ./ cb; dl = asin(sdl); lambda = dl / n + lambda0; w = log(tan(b / 2.0 + pi / 4.0)); q = (w - m) / n; phiprime = atan(exp(q)) * 2. - pi / 2.;

for i = 1:4 dq = e / 2.0 * log((e * sin(phiprime) + 1.) ./ (1. - e * sin(phiprime))); phi = atan(exp(q + dq)) * 2. - pi / 2.; phiprime = phi; end

lambda = lambda / pi * 180.; phi = phi / pi * 180.;

function [phiwgs,lamwgs]=bessel2wgs84(phibes, lambes) % convert Bessel2 WGS84

a = 52.0; b = 5.0; c = -96.862; d = 11.714; e = 0.125; f = 1e-5; g = 0.329; h = 37.902; i = 14.667;

dphi = phibes - a; dlam = lambes - b; phicor = (c - dphi * d - dlam * e) * f; lamcor = (dphi * g - h - dlam * i) * f; phiwgs = phibes + phicor; lamwgs = lambes + lamcor;

function [long,lat,LL]=selftest

%Amersfoort en andere punten x = [155000; 244000; 93000; 98000; 177000]; y = [463000; 601000; 464000; 471000; 439000];

[long,lat,LL]=rd2wgs(x,y);