TwoBodiesBaryTransformProvider.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.frames;
import org.hipparchus.CalculusFieldElement;
import org.hipparchus.geometry.euclidean.threed.FieldVector3D;
import org.hipparchus.geometry.euclidean.threed.Vector3D;
import org.orekit.bodies.CelestialBody;
import org.orekit.time.AbsoluteDate;
import org.orekit.time.FieldAbsoluteDate;
import org.orekit.utils.FieldPVCoordinates;
import org.orekit.utils.PVCoordinates;
/** Transform provider for the inertial Barycentered frame.
* @author Vincent Mouraux
* @since 10.2
*/
class TwoBodiesBaryTransformProvider implements TransformProvider {
/** Serializable UID.*/
private static final long serialVersionUID = 20190726L;
/** Frame for results. Always defined as primaryBody's inertially oriented frame.*/
private final Frame frame;
/** Celestial body with bigger mass, m1. */
private final CelestialBody primaryBody;
/** Celestial body with smaller mass, m2. */
private final CelestialBody secondaryBody;
/** Simple constructor.
* @param primaryBody Primary body.
* @param secondaryBody Secondary body.
*/
TwoBodiesBaryTransformProvider(final CelestialBody primaryBody, final CelestialBody secondaryBody) {
this.primaryBody = primaryBody;
this.secondaryBody = secondaryBody;
this.frame = primaryBody.getInertiallyOrientedFrame();
}
/** {@inheritDoc} */
@Override
public Transform getTransform(final AbsoluteDate date) {
final PVCoordinates pv21 = secondaryBody.getPVCoordinates(date, frame);
final double massRatio = secondaryBody.getGM() / (primaryBody.getGM() + secondaryBody.getGM());
final Vector3D translation = pv21.getPosition().scalarMultiply(massRatio).negate();
return new Transform(date, translation);
}
/** {@inheritDoc} */
@Override
public <T extends CalculusFieldElement<T>> FieldTransform<T> getTransform(final FieldAbsoluteDate<T> date) {
final FieldPVCoordinates<T> pv21 = secondaryBody.getPVCoordinates(date, frame);
final double massRatio = secondaryBody.getGM() / (primaryBody.getGM() + secondaryBody.getGM());
final FieldVector3D<T> translation = pv21.getPosition().scalarMultiply(massRatio).negate();
return new FieldTransform<>(date, translation);
}
}