Examples of org.osgeo.proj4j.datum.Ellipsoid

org.osgeo.proj4j.datum.Ellipsoid

A class representing a geographic reference ellipsoid (or more correctly an oblate spheroid), used to model the shape of the surface of the earth.

An oblate spheroid is a geometric surface formed by the rotation of an ellipse about its minor axis. In geodesy this is used as a convenient approximation to the geoid, the true shape of the earth's surface.

An ellipsoid is defined by the following parameters:

a, the equatorial radius or semi-major axis (see {@link #getA()})

and one of:

b, the polar radius or semi-minor axis (see {@link #getB()})
f, the reciprocal flattening (f = (a - b) / a)

In order to be used as a model of the geoid, the exact positioning of an ellipsoid relative to the geoid surface needs to be specified. This is provided by means of a geodetic {@link Datum}.

Notable ellipsoids in common use include {@link #CLARKE_1866}, {@link #GRS80}, and {@link #WGS84}. @see Datum

  
  public Ellipsoid getEllipsoid()
  {
    if (ellipsoid != null)
        return ellipsoid;
    return new Ellipsoid("user", a, es, "User-defined");
  }

    Proj4Keyword.checkUnsupported(params.keySet());
    DatumParameters datumParam = new DatumParameters();
    parseDatum(params, datumParam);
    parseEllipsoid(params, datumParam);
    Datum datum = datumParam.getDatum();
    Ellipsoid ellipsoid = datum.getEllipsoid(); 
    // TODO: this makes a difference - why?
    // which is better?
//    Ellipsoid ellipsoid = datumParam.getEllipsoid(); 
    Projection proj = parseProjection(params, ellipsoid);
    return new CoordinateReferenceSystem(name, args, datum, proj);

    * null) a = Double.parseDouble(s);
    */


   String code = (String) params.get(Proj4Keyword.ellps);
   if (code != null) {
     Ellipsoid ellipsoid = registry.getEllipsoid(code);
     if (ellipsoid == null)
       throw new InvalidValueException("Unknown ellipsoid: " + code);
     datumParam.setEllipsoid(ellipsoid);
   }

Examples of org.osgeo.proj4j.datum.Ellipsoid

Related Classes of org.osgeo.proj4j.datum.Ellipsoid