GeodeticCalculator

The GeodeticCalculator is used to perform calculations on the Geoid (i.e. on the surface of the world).

../../_images/geodetic_calculator.PNG

You can configure your GeodeticCalculator to work with a specific Ellipsoid (or commonly from an CoordinateReferenceSystem) and then use it to perform a number

References:

Distance

  • Distance between two points

            // the following code is based on JTS.orthodromicDistance( start, end, crs )
            GeodeticCalculator gc = new GeodeticCalculator(crs);
            gc.setStartingPosition(JTS.toDirectPosition(start, crs));
            gc.setDestinationPosition(JTS.toDirectPosition(end, crs));
    
            double distance = gc.getOrthodromicDistance();
    
            int totalmeters = (int) distance;
            int km = totalmeters / 1000;
            int meters = totalmeters - (km * 1000);
            float remaining_cm = (float) (distance - totalmeters) * 10000;
            remaining_cm = Math.round(remaining_cm);
            float cm = remaining_cm / 100;
    
            System.out.println("Distance = " + km + "km " + meters + "m " + cm + "cm");
    

    Although the above shows quickly creating a DirectPosition from a JTS Coordinate; you can use the GeodedicCalculator with any two positions, internally it will transform the points as needed.

  • You can also generate the angle between the two points

    Continuing on from the previous example:

            double angle = gc.getAzimuth();
    
            System.out.println("Angle = " + angle);
    
  • Generate location away from a point

    Finally you can turn the tables and use the GeodeticCalculator to generate a point a set direction and distance away from your starting point.

            GeodeticCalculator calc = new GeodeticCalculator();
            // mind, this is lon/lat
            calc.setStartingGeographicPoint(45.4644, 9.1908);
            calc.setDirection(90 /* azimuth */, 200 /* distance */);
            Point2D dest = calc.getDestinationGeographicPoint();
            System.out.println("Longitude: " + dest.getX() + " Latitude: " + dest.getY());