FrequencyPattern.java
/* Copyright 2002-2019 CS Systèmes d'Information
* Licensed to CS Systèmes d'Information (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.gnss.antenna;
import org.hipparchus.geometry.euclidean.threed.Vector3D;
import org.hipparchus.util.FastMath;
/**
* Pattern for GNSS antenna model on one frequency.
*
* @author Luc Maisonobe
* @since 9.2
* @see <a href="ftp://www.igs.org/pub/station/general/antex14.txt">ANTEX: The Antenna Exchange Format, Version 1.4</a>
*
*/
public class FrequencyPattern {
/** Phase center eccentricities (m). */
private final Vector3D eccentricities;
/** Phase center variation function. */
private final PhaseCenterVariationFunction phaseCenterVariationFunction;
/** Simple constructor.
* @param eccentricities phase center eccentricities (m)
* @param phaseCenterVariationFunction phase center variation function
*/
protected FrequencyPattern(final Vector3D eccentricities,
final PhaseCenterVariationFunction phaseCenterVariationFunction) {
this.eccentricities = eccentricities;
this.phaseCenterVariationFunction = phaseCenterVariationFunction;
}
/** Get the phase center eccentricities.
* @return phase center eccentricities (m)
*/
public Vector3D getEccentricities() {
return eccentricities;
}
/** Get the value of the phase center variation in a signal direction.
* @param direction signal direction in antenna reference frame
* @return value of the phase center variation
*/
public double getPhaseCenterVariation(final Vector3D direction) {
return phaseCenterVariationFunction.value(0.5 * FastMath.PI - direction.getDelta(),
direction.getAlpha());
}
}