Mercurial > dive4elements > gnv-client
diff gnv-artifacts/src/main/java/de/intevation/gnv/utils/DistanceCalculator.java @ 185:5fc8f41669a6
Added Calculation of the Distance in the unit km for Geodetic-Coordinates according to the Specification GT_0030.004
gnv-artifacts/trunk@229 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author | Tim Englich <tim.englich@intevation.de> |
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date | Fri, 16 Oct 2009 12:37:00 +0000 |
parents | |
children | da1499a464b9 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gnv-artifacts/src/main/java/de/intevation/gnv/utils/DistanceCalculator.java Fri Oct 16 12:37:00 2009 +0000 @@ -0,0 +1,65 @@ +/** + * + */ +package de.intevation.gnv.utils; + +import com.vividsolutions.jts.geom.Point; + +/** + * @author Tim Englich <tim.englich@intevation.de> + * + */ +public class DistanceCalculator { + + private final static double flattening = 1.0 / 298.257233563; + + private final static double earthRadius = 6378137.0 / 1000.0 ; + + /** + * Constructor + */ + public DistanceCalculator() { + } + + public double calculateDistance(Point p1, Point p2){ + double resultValue = 0.0; + + double b1 = p1.getY(); + double b2 = p2.getY(); + + double l1 = p1.getX(); + double l2 = p2.getX(); + + + double F = (b1 + b2) / 2.0; + double G = (b1 - b2) / 2.0; + double l = (l1 - l2) / 2.0; + + F = (Math.PI / 180.0) * F; + G = (Math.PI / 180.0) * G; + l = (Math.PI / 180.0) * l; + + double S = ((Math.sin(G) * Math.sin(G)) * ((Math.cos(l) * Math.cos(l))))+ + ((Math.cos(F) * Math.cos(F)) * ((Math.sin(l) * Math.sin(l)))); + + double C = ((Math.cos(G) * Math.cos(G)) * ((Math.cos(l) * Math.cos(l))))+ + ((Math.sin(F) * Math.sin(F)) * ((Math.sin(l) * Math.sin(l)))); + + double w = Math.atan(Math.sqrt((S/C))); + + double D = 2.0 * w * earthRadius; + + double R = Math.sqrt((S*C)) / w; + + double H1 = (3.0 * R - 1.0 ) / (2.0 * C); + double H2 = (3.0 * R + 1.0 ) / (2.0 * S); + + resultValue = D * (1 + (flattening * H1 * (Math.sin(F) * Math.sin(F)) * + (Math.cos(G) * Math.cos(G))) - + (flattening * H2 * (Math.cos(F) * Math.cos(F)) * + (Math.sin(G) * Math.sin(G)))); + + return resultValue; + } + +}