/*
* Copyright 1998-2009 University Corporation for Atmospheric Research/Unidata
*
* Portions of this software were developed by the Unidata Program at the
* University Corporation for Atmospheric Research.
*
* Access and use of this software shall impose the following obligations
* and understandings on the user. The user is granted the right, without
* any fee or cost, to use, copy, modify, alter, enhance and distribute
* this software, and any derivative works thereof, and its supporting
* documentation for any purpose whatsoever, provided that this entire
* notice appears in all copies of the software, derivative works and
* supporting documentation. Further, UCAR requests that the user credit
* UCAR/Unidata in any publications that result from the use of this
* software or in any product that includes this software. The names UCAR
* and/or Unidata, however, may not be used in any advertising or publicity
* to endorse or promote any products or commercial entity unless specific
* written permission is obtained from UCAR/Unidata. The user also
* understands that UCAR/Unidata is not obligated to provide the user with
* any support, consulting, training or assistance of any kind with regard
* to the use, operation and performance of this software nor to provide
* the user with any updates, revisions, new versions or "bug fixes."
*
* THIS SOFTWARE IS PROVIDED BY UCAR/UNIDATA "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL UCAR/UNIDATA BE LIABLE FOR ANY SPECIAL,
* INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE.
*/
package ucar.nc2.dataset.transform;
import ucar.nc2.dataset.CoordinateTransform;
import ucar.nc2.dataset.ProjectionCT;
import ucar.nc2.dataset.NetcdfDataset;
import ucar.nc2.dataset.TransformType;
import ucar.nc2.Variable;
import ucar.unidata.geoloc.projection.proj4.AlbersEqualAreaEllipse;
import ucar.unidata.geoloc.Earth;
/**
* Create a AlbersEqualArea Projection from the information in the Coordinate Transform Variable.
*
* @author caron
*/
public class AlbersEqualArea extends AbstractCoordTransBuilder {
public String getTransformName() {
return "albers_conical_equal_area";
}
public TransformType getTransformType() {
return TransformType.Projection;
}
public CoordinateTransform makeCoordinateTransform(NetcdfDataset ds, Variable ctv) {
double[] pars = readAttributeDouble2(ctv.findAttribute("standard_parallel"));
if (pars == null) return null;
double lon0 = readAttributeDouble(ctv, "longitude_of_central_meridian", Double.NaN);
double lat0 = readAttributeDouble(ctv, "latitude_of_projection_origin", Double.NaN);
double false_easting = readAttributeDouble(ctv, "false_easting", 0.0);
double false_northing = readAttributeDouble(ctv, "false_northing", 0.0);
if ((false_easting != 0.0) || (false_northing != 0.0)) {
double scalef = getFalseEastingScaleFactor(ds, ctv);
false_easting *= scalef;
false_northing *= scalef;
}
// these must be in meters, projection needs them in km
double earth_radius = readAttributeDouble(ctv, "earth_radius", Earth.getRadius()) * .001;
double semi_major_axis = readAttributeDouble(ctv, "semi_major_axis", Double.NaN);
double semi_minor_axis = readAttributeDouble(ctv, "semi_minor_axis", Double.NaN);
double inverse_flattening = readAttributeDouble(ctv, "inverse_flattening", 0.0);
ucar.unidata.geoloc.ProjectionImpl proj;
// check for ellipsoidal earth
if (!Double.isNaN(semi_major_axis) && (!Double.isNaN(semi_minor_axis) || inverse_flattening != 0.0)) {
Earth earth = new Earth(semi_major_axis, semi_minor_axis, inverse_flattening);
proj = new AlbersEqualAreaEllipse(lat0, lon0, pars[0], pars[1], false_easting, false_northing, earth);
} else {
proj = new ucar.unidata.geoloc.projection.AlbersEqualArea(lat0, lon0, pars[0], pars[1], false_easting, false_northing, earth_radius);
}
return new ProjectionCT(ctv.getShortName(), "FGDC", proj);
}
}