org.cts.op.projection.GaussSchreiberTransverseMercator Maven / Gradle / Ivy
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/*
* Coordinate Transformations Suite (abridged CTS) is a library developped to
* perform Coordinate Transformations using well known geodetic algorithms
* and parameter sets.
* Its main focus are simplicity, flexibility, interoperability, in this order.
*
* This library has been originally developed by Michaël Michaud under the JGeod
* name. It has been renamed CTS in 2009 and shared to the community from
* the OrbisGIS code repository.
*
* CTS is free software: you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free Software
* Foundation, either version 3 of the License.
*
* CTS is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
* A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License along with
* CTS. If not, see
*
* @author Jules Party
*/
public class GaussSchreiberTransverseMercator extends Projection {
/**
* The Identifier used for all Gauss Schreiber Transverse Mercator
* projections.
*/
public static final Identifier GSTMERC =
new Identifier("IGNF", "REUN47GAUSSL", "Gauss Schreiber Transverse Mercator (aka Gauss Laborde Réunion", "GSTMERC");
protected final double lon0, // the reference longitude (from the datum prime meridian)
latc, // latitude of the origin on the medium sphere
c, // constant of the projection
n1, // exponent of the ellipsoid to sphere projection
n2, // radius of the medium sphere
xs, // x coordinate of the pole
ys; // y coordinate of the pole
/**
* Create a new Gauss Schreiber Transverse Mercator Projection corresponding
* to the
* Ellipsoid and the list of parameters given in argument and
* initialize common parameters lon0 and other parameters useful for the
* projection.
*
* @param ellipsoid ellipsoid used to define the projection.
* @param parameters a map of useful parameters to define the projection.
*/
public GaussSchreiberTransverseMercator(final Ellipsoid ellipsoid,
final Map parameters) {
super(GSTMERC, ellipsoid, parameters);
lon0 = getCentralMeridian();
double lat0 = getLatitudeOfOrigin();
double FE = getFalseEasting();
double FN = getFalseNorthing();
double k0 = getScaleFactor();
double e2 = ellipsoid.getSquareEccentricity();
n1 = sqrt(1 + e2 / (1 - e2) * pow(cos(lat0), 4));
latc = asin(sin(lat0) / n1);
c = Ellipsoid.SPHERE.isometricLatitude(latc) - n1 * ellipsoid.isometricLatitude(lat0);
n2 = k0 * ellipsoid.getSemiMajorAxis() * sqrt(1 - e2) / (1 - e2 * sin(lat0) * sin(lat0));
xs = FE;
ys = FN - n2 * latc;
}
/**
* Return the
* Surface type of this
* Projection.
*/
@Override
public Surface getSurface() {
return Projection.Surface.PSEUDOCYLINDRICAL;
}
/**
* Return the
* Property of this
* Projection.
*/
@Override
public Property getProperty() {
return Projection.Property.APHYLACTIC;
}
/**
* Return the
* Orientation of this
* Projection.
*/
@Override
public Orientation getOrientation() {
return Projection.Orientation.TRANSVERSE;
}
/**
* Transform coord using the Gauss Schreiber Transverse Mercator Projection.
* Input coord is supposed to be a geographic latitude / longitude
* coordinate in radians. Algorithm based on the OGP's Guidance Note Number
* 7 Part 2 :
*
*
* @param coord coordinate to transform
* @throws CoordinateDimensionException if coord length is not
* compatible with this CoordinateOperation.
*/
@Override
public double[] transform(double[] coord) throws CoordinateDimensionException {
double Lambda = n1 * (coord[1] - lon0);
double isoLats = c + n1 * ellipsoid.isometricLatitude(coord[0]);
coord[0] = xs + n2 * Ellipsoid.SPHERE.isometricLatitude(asin(sin(Lambda) / cosh(isoLats)));
coord[1] = ys + n2 * atan(sinh(isoLats) / cos(Lambda));
return coord;
}
/**
* Creates the inverse operation for Gauss Schreiber Transverse Mercator
* Projection. Input coord is supposed to be a projected easting / northing
* coordinate in meters. Algorithm based on the OGP's Guidance Note Number 7
* Part 2 :
*
*/
@Override
public Projection inverse() throws NonInvertibleOperationException {
return new GaussSchreiberTransverseMercator(ellipsoid, parameters) {
@Override
public double[] transform(double[] coord) throws CoordinateDimensionException {
double Lambda = atan(sinh((coord[0] - xs) / n2) / cos((coord[1] - ys) / n2));
double isoLats = Ellipsoid.SPHERE.isometricLatitude(asin(sin((coord[1] - ys) / n2) / cosh((coord[0] - xs) / n2)));
coord[0] = ellipsoid.latitude((isoLats - c) / n1);
coord[1] = lon0 + Lambda / n1;
return coord;
}
@Override
public Projection inverse()
throws NonInvertibleOperationException {
return GaussSchreiberTransverseMercator.this;
}
@Override
public boolean isDirect() {
return false;
}
@Override
public String toString() {
return GaussSchreiberTransverseMercator.this.toString() + " inverse";
}
};
}
}