Coastlines/utm2deg.m

134 lines
3.9 KiB
Matlab

function [Lat,Lon] = utm2deg(xx,yy,utmzone)
% -------------------------------------------------------------------------
% [Lat,Lon] = utm2deg(x,y,utmzone)
%
% Description: Function to convert vectors of UTM coordinates into Lat/Lon vectors (WGS84).
% Some code has been extracted from UTMIP.m function by Gabriel Ruiz Martinez.
%
% Inputs:
% x, y , utmzone.
%
% Outputs:
% Lat: Latitude vector. Degrees. +ddd.ddddd WGS84
% Lon: Longitude vector. Degrees. +ddd.ddddd WGS84
%
% Example 1:
% x=[ 458731; 407653; 239027; 230253; 343898; 362850];
% y=[4462881; 5126290; 4163083; 3171843; 4302285; 2772478];
% utmzone=['30 T'; '32 T'; '11 S'; '28 R'; '15 S'; '51 R'];
% [Lat, Lon]=utm2deg(x,y,utmzone);
% fprintf('%11.6f ',lat)
% 40.315430 46.283902 37.577834 28.645647 38.855552 25.061780
% fprintf('%11.6f ',lon)
% -3.485713 7.801235 -119.955246 -17.759537 -94.799019 121.640266
%
% Example 2: If you need Lat/Lon coordinates in Degrees, Minutes and Seconds
% [Lat, Lon]=utm2deg(x,y,utmzone);
% LatDMS=dms2mat(deg2dms(Lat))
%LatDMS =
% 40.00 18.00 55.55
% 46.00 17.00 2.01
% 37.00 34.00 40.17
% 28.00 38.00 44.33
% 38.00 51.00 19.96
% 25.00 3.00 42.41
% LonDMS=dms2mat(deg2dms(Lon))
%LonDMS =
% -3.00 29.00 8.61
% 7.00 48.00 4.40
% -119.00 57.00 18.93
% -17.00 45.00 34.33
% -94.00 47.00 56.47
% 121.00 38.00 24.96
%
% Author:
% Rafael Palacios
% Universidad Pontificia Comillas
% Madrid, Spain
% Version: Apr/06, Jun/06, Aug/06
% Aug/06: corrected m-Lint warnings
%-------------------------------------------------------------------------
% Argument checking
%
error(nargchk(3, 3, nargin)); %3 arguments required
n1=length(xx);
n2=length(yy);
n3=size(utmzone,1);
if (n1~=n2 || n1~=n3)
error('x,y and utmzone vectors should have the same number or rows');
end
c=size(utmzone,2);
if (c~=4)
error('utmzone should be a vector of strings like "30 T"');
end
% Memory pre-allocation
%
Lat=zeros(n1,1);
Lon=zeros(n1,1);
% Main Loop
%
for i=1:n1
if (utmzone(i,4)>'X' || utmzone(i,4)<'C')
fprintf('utm2deg: Warning utmzone should be a vector of strings like "30 T", not "30 t"\n');
end
if (utmzone(i,4)>'M')
hemis='N'; % Northern hemisphere
else
hemis='S';
end
x=xx(i);
y=yy(i);
zone=str2double(utmzone(i,1:2));
sa = 6378137.000000 ; sb = 6356752.314245;
% e = ( ( ( sa ^ 2 ) - ( sb ^ 2 ) ) ^ 0.5 ) / sa;
e2 = ( ( ( sa ^ 2 ) - ( sb ^ 2 ) ) ^ 0.5 ) / sb;
e2cuadrada = e2 ^ 2;
c = ( sa ^ 2 ) / sb;
% alpha = ( sa - sb ) / sa; %f
% ablandamiento = 1 / alpha; % 1/f
X = x - 500000;
if hemis == 'S' || hemis == 's'
Y = y - 10000000;
else
Y = y;
end
S = ( ( zone * 6 ) - 183 );
lat = Y / ( 6366197.724 * 0.9996 );
v = ( c / ( ( 1 + ( e2cuadrada * ( cos(lat) ) ^ 2 ) ) ) ^ 0.5 ) * 0.9996;
a = X / v;
a1 = sin( 2 * lat );
a2 = a1 * ( cos(lat) ) ^ 2;
j2 = lat + ( a1 / 2 );
j4 = ( ( 3 * j2 ) + a2 ) / 4;
j6 = ( ( 5 * j4 ) + ( a2 * ( cos(lat) ) ^ 2) ) / 3;
alfa = ( 3 / 4 ) * e2cuadrada;
beta = ( 5 / 3 ) * alfa ^ 2;
gama = ( 35 / 27 ) * alfa ^ 3;
Bm = 0.9996 * c * ( lat - alfa * j2 + beta * j4 - gama * j6 );
b = ( Y - Bm ) / v;
Epsi = ( ( e2cuadrada * a^ 2 ) / 2 ) * ( cos(lat) )^ 2;
Eps = a * ( 1 - ( Epsi / 3 ) );
nab = ( b * ( 1 - Epsi ) ) + lat;
senoheps = ( exp(Eps) - exp(-Eps) ) / 2;
Delt = atan(senoheps / (cos(nab) ) );
TaO = atan(cos(Delt) * tan(nab));
longitude = (Delt *(180 / pi ) ) + S;
latitude = ( lat + ( 1 + e2cuadrada* (cos(lat)^ 2) - ( 3 / 2 ) * e2cuadrada * sin(lat) * cos(lat) * ( TaO - lat ) ) * ( TaO - lat ) ) * ...
(180 / pi);
Lat(i)=latitude;
Lon(i)=longitude;
end