DSST6X0OrbitalState.java
- /* Copyright 2020-2024 Exotrail
- * 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.propagation.conversion.averaging;
- import org.orekit.forces.gravity.potential.UnnormalizedSphericalHarmonicsProvider;
- import org.orekit.frames.Frame;
- import org.orekit.orbits.EquinoctialOrbit;
- import org.orekit.orbits.Orbit;
- import org.orekit.orbits.OrbitType;
- import org.orekit.orbits.PositionAngleType;
- import org.orekit.propagation.SpacecraftState;
- import org.orekit.propagation.semianalytical.dsst.DSSTPropagator;
- import org.orekit.propagation.semianalytical.dsst.forces.DSSTForceModel;
- import org.orekit.propagation.semianalytical.dsst.forces.DSSTZonal;
- import org.orekit.time.AbsoluteDate;
- import org.orekit.propagation.conversion.averaging.elements.AveragedEquinoctialWithMeanAngle;
- import java.util.ArrayList;
- import java.util.Collection;
- import java.util.List;
- /**
- * Class representing an averaged orbital state as in the DSST theory using only the first 6 zonal
- * harmonics as perturbations.
- *
- * @author Romain Serra
- * @see AveragedOrbitalState
- * @see DSSTPropagator
- * @see DSSTZonal
- * @since 12.1
- */
- public class DSST6X0OrbitalState extends AbstractHarmonicsBasedOrbitalState {
- /** Averaged equinoctial elements. */
- private final AveragedEquinoctialWithMeanAngle averagedElements;
- /**
- * Constructor.
- * @param date epoch
- * @param elements averaged orbital elements
- * @param frame reference frame
- * @param harmonicsProvider spherical harmonics provider
- */
- public DSST6X0OrbitalState(final AbsoluteDate date,
- final AveragedEquinoctialWithMeanAngle elements,
- final Frame frame,
- final UnnormalizedSphericalHarmonicsProvider harmonicsProvider) {
- super(date, frame, harmonicsProvider);
- this.averagedElements = elements;
- }
- /**
- * Create collection of fist 6 zonal DSST forces.
- * @param provider spherical harmonics provider
- * @return six first zonal forces
- */
- public static Collection<DSSTForceModel> createForces(final UnnormalizedSphericalHarmonicsProvider provider) {
- final List<DSSTForceModel> forceModels = new ArrayList<>();
- final DSSTZonal zonal = new DSSTZonal(provider);
- forceModels.add(zonal);
- return forceModels;
- }
- /** {@inheritDoc} */
- @Override
- public OrbitType getOrbitType() {
- return OrbitType.EQUINOCTIAL;
- }
- /** {@inheritDoc} */
- @Override
- public PositionAngleType getPositionAngleType() {
- return PositionAngleType.MEAN;
- }
- /** {@inheritDoc} */
- @Override
- public AveragedEquinoctialWithMeanAngle getAveragedElements() {
- return averagedElements;
- }
- /** {@inheritDoc} */
- @Override
- public Orbit toOsculatingOrbit() {
- final EquinoctialOrbit orekitOrbit = createOrekitOrbit();
- final Collection<DSSTForceModel> forceModels = createForces(getHarmonicsProvider());
- final SpacecraftState osculatingState = DSSTPropagator.computeOsculatingState(
- new SpacecraftState(orekitOrbit), null, forceModels);
- return osculatingState.getOrbit();
- }
- /**
- * Create equinoctial orbit representation of averaged state.
- * @return equinoctial orbit
- */
- private EquinoctialOrbit createOrekitOrbit() {
- return new EquinoctialOrbit(averagedElements.getAveragedSemiMajorAxis(),
- averagedElements.getAveragedEquinoctialEx(),
- averagedElements.getAveragedEquinoctialEy(),
- averagedElements.getAveragedHx(), averagedElements.getAveragedHy(),
- averagedElements.getAveragedMeanLongitudeArgument(),
- getPositionAngleType(), getFrame(), getDate(), getMu());
- }
- }