ConstantAzimuthAiming.java
/* Copyright 2002-2024 CS GROUP
* Licensed to CS GROUP (CS) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* CS licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.orekit.models.earth.tessellation;
import java.util.Arrays;
import java.util.List;
import org.hipparchus.geometry.euclidean.threed.Vector3D;
import org.hipparchus.util.FastMath;
import org.hipparchus.util.SinCos;
import org.orekit.bodies.GeodeticPoint;
import org.orekit.bodies.OneAxisEllipsoid;
/** Class used to orient tiles with respect to a geographic azimuth.
* @see AlongTrackAiming
* @see DivertedSingularityAiming
* @author Luc Maisonobe
*/
public class ConstantAzimuthAiming implements TileAiming {
/** Sine and Cosine of the azimuth. */
private final SinCos sc;
/** Simple constructor.
* @param ellipsoid ellipsoid body on which the zone is defined
* @param azimuth geographic azimuth of the tiles
*/
public ConstantAzimuthAiming(final OneAxisEllipsoid ellipsoid, final double azimuth) {
this.sc = FastMath.sinCos(azimuth);
}
/** {@inheritDoc} */
@Override
public List<GeodeticPoint> getSingularPoints() {
return Arrays.asList(GeodeticPoint.NORTH_POLE, GeodeticPoint.SOUTH_POLE);
}
/** {@inheritDoc} */
@Override
public Vector3D alongTileDirection(final Vector3D point, final GeodeticPoint gp) {
// compute the horizontal direction at fixed azimuth
return new Vector3D(sc.cos(), gp.getNorth(), sc.sin(), gp.getEast());
}
}