J2SquaredModel.java
- /* Copyright 2022 Bryan Cazabonne
- * 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.
- * Bryan Cazabonne 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.semianalytical.dsst.forces;
- import org.hipparchus.CalculusFieldElement;
- import org.orekit.propagation.FieldSpacecraftState;
- import org.orekit.propagation.PropagationType;
- import org.orekit.propagation.SpacecraftState;
- import org.orekit.propagation.semianalytical.dsst.utilities.AuxiliaryElements;
- import org.orekit.propagation.semianalytical.dsst.utilities.FieldAuxiliaryElements;
- import java.util.Collections;
- import java.util.List;
- /**
- * Semi-analytical J2-squared model.
- * <p>
- * This interface is implemented by models providing J2-squared
- * second-order terms in equinoctial elements. These terms are
- * used in the computation of the closed-form J2-squared perturbation
- * in semi-analytical satellite theory.
- * </p>
- * @see ZeisModel
- * @author Bryan Cazabonne
- * @since 12.0
- */
- public interface J2SquaredModel {
- /**
- * Compute the J2-squared second-order terms in equinoctial elements.
- * @param context model context
- * @return the J2-squared second-order terms in equinoctial elements.
- * Order must follow: [A, K, H, Q, P, M]
- */
- double[] computeMeanEquinoctialSecondOrderTerms(DSSTJ2SquaredClosedFormContext context);
- /**
- * Compute the J2-squared second-order terms in equinoctial elements.
- * @param context model context
- * @param <T> type of the elements
- * @return the J2-squared second-order terms in equinoctial elements.
- * Order must follow: [A, K, H, Q, P, M]
- */
- <T extends CalculusFieldElement<T>> T[] computeMeanEquinoctialSecondOrderTerms(FieldDSSTJ2SquaredClosedFormContext<T> context);
- /**
- * Performs initialization of J2-squared short period terms prior to propagation.
- * @param auxiliaryElements auxiliary elements
- * @param type type of the elements used (MEAN or OSCULATING)
- * @param parameters force model parameters
- * @return a list containing the initialized short period terms
- * @since 12.2
- */
- default List<ShortPeriodTerms> initializeShortPeriodTerms(final AuxiliaryElements auxiliaryElements,
- final PropagationType type,
- final double[] parameters) {
- return Collections.emptyList();
- }
- /**
- * Performs initialization of J2-squared short period terms prior to propagation.
- * @param auxiliaryElements auxiliary elements
- * @param type type of the orbital elements used (MEAN or OSCULATING)
- * @param parameters force model parameters
- * @param <T> type of the field elements
- * @return a list containing the initialized short period terms
- * @since 12.2
- */
- default <T extends CalculusFieldElement<T>> List<FieldShortPeriodTerms<T>> initializeShortPeriodTerms(final FieldAuxiliaryElements<T> auxiliaryElements,
- final PropagationType type,
- final T[] parameters) {
- return Collections.emptyList();
- }
- /** Update the J2-squared short period terms.
- * <p>
- * The {@link ShortPeriodTerms short period terms} that will be updated
- * are the ones that were returned during the call to {@link
- * #initializeShortPeriodTerms(AuxiliaryElements, PropagationType, double[])}.
- * </p>
- * @param parameters force model parameters
- * @param meanStates mean states information: date, kinematics, attitude
- * @since 12.2
- */
- default void updateShortPeriodTerms(final double[] parameters, final SpacecraftState... meanStates) {
- // Does nothing by default
- }
- /** Update the J2-squared short period terms.
- * <p>
- * The {@link ShortPeriodTerms short period terms} that will be updated
- * are the ones that were returned during the call to {@link
- * #initializeShortPeriodTerms(AuxiliaryElements, PropagationType, double[])}.
- * </p>
- * @param parameters force model parameters
- * @param meanStates mean states information: date, kinematics, attitude
- * @param <T> type of the field elements
- * @since 12.2
- */
- @SuppressWarnings("unchecked")
- default <T extends CalculusFieldElement<T>> void updateShortPeriodTerms(final T[] parameters, final FieldSpacecraftState<T>... meanStates) {
- // Does nothing by default
- }
- }