DefaultEncounterLOF.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,
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*/
package org.orekit.frames.encounter;
import org.hipparchus.CalculusFieldElement;
import org.hipparchus.Field;
import org.hipparchus.geometry.euclidean.threed.FieldRotation;
import org.hipparchus.geometry.euclidean.threed.FieldVector3D;
import org.hipparchus.geometry.euclidean.threed.Rotation;
import org.hipparchus.geometry.euclidean.threed.Vector3D;
import org.orekit.utils.FieldPVCoordinates;
import org.orekit.utils.PVCoordinates;
/**
* Default encounter local orbital frame.
* <p>
* Note that <b>it is up to the user</b> to choose which object should be at the origin.
* <p>
* It is defined as follows :
* <ul>
* <li>z axis : Normalized relative velocity vector.</li>
* <li>y axis : Normalized cross product between z axis and other relative to origin position.</li>
* <li>x axis : Completes the right handed coordinate system.</li>
* </ul>
*
* @author Vincent Cucchietti
* @since 12.0
*/
public class DefaultEncounterLOF extends AbstractEncounterLOF {
/**
* Constructor.
*
* @param other other object to create the encounter frame with (not the origin of the frame !)
*/
public DefaultEncounterLOF(final PVCoordinates other) {
super(other);
}
/**
* Field constructor.
*
* @param other other object to create the encounter frame with (not the origin of the frame !)
* @param <T> type of the field elements
*/
public <T extends CalculusFieldElement<T>> DefaultEncounterLOF(final FieldPVCoordinates<T> other) {
super(other);
}
/** {@inheritDoc} */
@Override
public Rotation rotationFromInertial(final PVCoordinates origin, final PVCoordinates other) {
final Vector3D zAxis = other.getVelocity().subtract(origin.getVelocity()).normalize();
final Vector3D yAxis = zAxis.crossProduct(other.getPosition().subtract(origin.getPosition()));
return new Rotation(yAxis, zAxis, Vector3D.PLUS_J, Vector3D.PLUS_K);
}
/**
* {@inheritDoc}
* <p>
* In this case, return (0,0,1);
*/
@Override
public <T extends CalculusFieldElement<T>> FieldVector3D<T> getAxisNormalToCollisionPlane(final Field<T> field) {
return FieldVector3D.getPlusK(field);
}
/** {@inheritDoc} */
@Override
public <T extends CalculusFieldElement<T>> FieldRotation<T> rotationFromInertial(final Field<T> field,
final FieldPVCoordinates<T> origin,
final FieldPVCoordinates<T> other) {
final FieldVector3D<T> otherVelocity = other.getVelocity();
final FieldVector3D<T> otherPosition = other.getPosition();
final FieldVector3D<T> zAxis = otherVelocity.subtract(origin.getVelocity()).normalize();
final FieldVector3D<T> yAxis = zAxis.crossProduct(otherPosition.subtract(origin.getPosition()));
return new FieldRotation<>(yAxis, zAxis, FieldVector3D.getPlusJ(field), FieldVector3D.getPlusK(field));
}
/**
* {@inheritDoc}
* <p>
* In this case, return (0,0,1);
*/
@Override
public Vector3D getAxisNormalToCollisionPlane() {
return Vector3D.PLUS_K;
}
/** {@inheritDoc} */
@Override
public String getName() {
return "DEFAULT_ENCOUNTER_LOF";
}
}