LyapunovOrbit.java

/* Copyright 2002-2022 CS GROUP
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 * CS licenses this file to You under the Apache License, Version 2.0
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 *
 *   http://www.apache.org/licenses/LICENSE-2.0
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package org.orekit.orbits;

import org.orekit.bodies.CR3BPSystem;
import org.orekit.utils.PVCoordinates;

/** Class calculating different parameters of a Lyapunov Orbit.
 * @author Vincent Mouraux
 * @since 10.2
 */
public class LyapunovOrbit extends LibrationOrbit {

    /**
     * Simple Constructor.
     * <p>
     * This constructor can be used if the user wants to use a first guess from
     * any other sources or if he has the initial conditions of a well defined Lyapunov Orbit.
     * In that case, it is assumed that the user knows the
     * characteristics of the Lyapunov Orbit leading to this first guess/point. Also, the
     * orbital period of this Lyapunov Orbit has to be specified for further
     * computation.
     * </p>
     * @param syst CR3BP System considered
     * @param pv PVCoordinates of the initial point or of the first guess
     * @param orbitalPeriod Normalized orbital period linked to the given Lyapunov Orbit first guess
     */
    public LyapunovOrbit(final CR3BPSystem syst,
                         final PVCoordinates pv, final double orbitalPeriod) {
        super(syst, pv, orbitalPeriod);
    }

    /**
     * Simple Constructor.
     * <p>
     * Standard constructor, the first guess will be computed with both start
     * time and phase equal to zero.
     * </p>
     * @param richardson third-Order Richardson Expansion
     * @param ay y-axis amplitude of the required Lyapunov Orbit, meters
     */
    public LyapunovOrbit(final RichardsonExpansion richardson,
                         final double ay) {
        super(richardson.getCr3bpSystem(),
              richardson.computeLyapunovFirstGuess(ay, 0.0, 0.0),
              richardson.getLyapunovOrbitalPeriod(ay));
    }

    /** {@inheritDoc} */
    @Override
    protected PVCoordinates applyCorrectionOnPV(final CR3BPDifferentialCorrection diff) {
        return diff.compute(LibrationOrbitType.LYAPUNOV);
    }

}