EcksteinHechlerPropagatorBuilder.java
- /* Copyright 2002-2020 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.propagation.conversion;
- import org.orekit.annotation.DefaultDataContext;
- import org.orekit.attitudes.AttitudeProvider;
- import org.orekit.data.DataContext;
- import org.orekit.forces.gravity.potential.GravityFieldFactory;
- import org.orekit.forces.gravity.potential.TideSystem;
- import org.orekit.forces.gravity.potential.UnnormalizedSphericalHarmonicsProvider;
- import org.orekit.orbits.Orbit;
- import org.orekit.orbits.OrbitType;
- import org.orekit.orbits.PositionAngle;
- import org.orekit.propagation.Propagator;
- import org.orekit.propagation.analytical.EcksteinHechlerPropagator;
- /** Builder for Eckstein-Hechler propagator.
- * @author Pascal Parraud
- * @since 6.0
- */
- public class EcksteinHechlerPropagatorBuilder extends AbstractPropagatorBuilder {
- /** Provider for un-normalized coefficients. */
- private final UnnormalizedSphericalHarmonicsProvider provider;
- /** Build a new instance.
- * <p>
- * The template orbit is used as a model to {@link
- * #createInitialOrbit() create initial orbit}. It defines the
- * inertial frame, the central attraction coefficient, the orbit type, and is also
- * used together with the {@code positionScale} to convert from the {@link
- * org.orekit.utils.ParameterDriver#setNormalizedValue(double) normalized} parameters used by the
- * callers of this builder to the real orbital parameters.
- * </p>
- *
- * <p>This constructor uses the {@link DataContext#getDefault() default data context}.
- *
- * @param templateOrbit reference orbit from which real orbits will be built
- * (note that the mu from this orbit will be overridden with the mu from the
- * {@code provider})
- * @param provider for un-normalized zonal coefficients
- * @param positionAngle position angle type to use
- * @param positionScale scaling factor used for orbital parameters normalization
- * (typically set to the expected standard deviation of the position)
- * @since 8.0
- * @see #EcksteinHechlerPropagatorBuilder(Orbit,
- * UnnormalizedSphericalHarmonicsProvider, PositionAngle, double, AttitudeProvider)
- */
- @DefaultDataContext
- public EcksteinHechlerPropagatorBuilder(final Orbit templateOrbit,
- final UnnormalizedSphericalHarmonicsProvider provider,
- final PositionAngle positionAngle,
- final double positionScale) {
- this(templateOrbit, provider, positionAngle, positionScale,
- Propagator.getDefaultLaw(DataContext.getDefault().getFrames()));
- }
- /** Build a new instance.
- * <p>
- * The template orbit is used as a model to {@link
- * #createInitialOrbit() create initial orbit}. It defines the
- * inertial frame, the central attraction coefficient, the orbit type, and is also
- * used together with the {@code positionScale} to convert from the {@link
- * org.orekit.utils.ParameterDriver#setNormalizedValue(double) normalized} parameters used by the
- * callers of this builder to the real orbital parameters.
- * </p>
- * @param templateOrbit reference orbit from which real orbits will be built
- * (note that the mu from this orbit will be overridden with the mu from the
- * {@code provider})
- * @param provider for un-normalized zonal coefficients
- * @param positionAngle position angle type to use
- * @param positionScale scaling factor used for orbital parameters normalization
- * (typically set to the expected standard deviation of the position)
- * @param attitudeProvider attitude law to use.
- * @since 10.1
- */
- public EcksteinHechlerPropagatorBuilder(final Orbit templateOrbit,
- final UnnormalizedSphericalHarmonicsProvider provider,
- final PositionAngle positionAngle,
- final double positionScale,
- final AttitudeProvider attitudeProvider) {
- super(overrideMu(templateOrbit, provider, positionAngle), positionAngle,
- positionScale, true, attitudeProvider);
- this.provider = provider;
- }
- /** Build a new instance.
- * <p>
- * The template orbit is used as a model to {@link
- * #createInitialOrbit() create initial orbit}. It defines the
- * inertial frame, the central attraction coefficient, the orbit type, and is also
- * used together with the {@code positionScale} to convert from the {@link
- * org.orekit.utils.ParameterDriver#setNormalizedValue(double) normalized} parameters used by the
- * callers of this builder to the real orbital parameters.
- * </p>
- *
- * <p>This constructor uses the {@link DataContext#getDefault() default data context}.
- *
- * @param templateOrbit reference orbit from which real orbits will be built
- * (note that the mu from this orbit will be overridden with the mu from the
- * {@code provider})
- * @param referenceRadius reference radius of the Earth for the potential model (m)
- * @param mu central attraction coefficient (m³/s²)
- * @param tideSystem tide system
- * @param c20 un-normalized zonal coefficient (about -1.08e-3 for Earth)
- * @param c30 un-normalized zonal coefficient (about +2.53e-6 for Earth)
- * @param c40 un-normalized zonal coefficient (about +1.62e-6 for Earth)
- * @param c50 un-normalized zonal coefficient (about +2.28e-7 for Earth)
- * @param c60 un-normalized zonal coefficient (about -5.41e-7 for Earth)
- * @param orbitType orbit type to use
- * @param positionAngle position angle type to use
- * @param positionScale scaling factor used for orbital parameters normalization
- * (typically set to the expected standard deviation of the position)
- * @since 8.0
- * @see #EcksteinHechlerPropagatorBuilder(Orbit,
- * UnnormalizedSphericalHarmonicsProvider, PositionAngle, double, AttitudeProvider)
- */
- @DefaultDataContext
- public EcksteinHechlerPropagatorBuilder(final Orbit templateOrbit,
- final double referenceRadius,
- final double mu,
- final TideSystem tideSystem,
- final double c20,
- final double c30,
- final double c40,
- final double c50,
- final double c60,
- final OrbitType orbitType,
- final PositionAngle positionAngle,
- final double positionScale) {
- this(templateOrbit,
- GravityFieldFactory.getUnnormalizedProvider(referenceRadius, mu, tideSystem,
- new double[][] {
- {
- 0
- }, {
- 0
- }, {
- c20
- }, {
- c30
- }, {
- c40
- }, {
- c50
- }, {
- c60
- }
- }, new double[][] {
- {
- 0
- }, {
- 0
- }, {
- 0
- }, {
- 0
- }, {
- 0
- }, {
- 0
- }, {
- 0
- }
- }),
- positionAngle, positionScale);
- }
- /** Override central attraction coefficient.
- * @param templateOrbit template orbit
- * @param provider gravity field provider
- * @param positionAngle position angle type to use
- * @return orbit with overridden central attraction coefficient
- */
- private static Orbit overrideMu(final Orbit templateOrbit,
- final UnnormalizedSphericalHarmonicsProvider provider,
- final PositionAngle positionAngle) {
- final double[] parameters = new double[6];
- final double[] parametersDot = templateOrbit.hasDerivatives() ? new double[6] : null;
- templateOrbit.getType().mapOrbitToArray(templateOrbit, positionAngle, parameters, parametersDot);
- return templateOrbit.getType().mapArrayToOrbit(parameters, parametersDot, positionAngle,
- templateOrbit.getDate(),
- provider.getMu(),
- templateOrbit.getFrame());
- }
- /** {@inheritDoc} */
- public Propagator buildPropagator(final double[] normalizedParameters) {
- setParameters(normalizedParameters);
- return new EcksteinHechlerPropagator(createInitialOrbit(), getAttitudeProvider(),
- provider);
- }
- }