AbstractBodyAttraction.java
- /* Copyright 2022-2024 Romain Serra
- * 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.forces.gravity;
- import org.hipparchus.util.FastMath;
- import org.orekit.bodies.CelestialBody;
- import org.orekit.forces.ForceModel;
- import org.orekit.utils.ParameterDriver;
- import java.util.Collections;
- import java.util.List;
- /** Abstract class for body attraction force model.
- *
- * @author Romain Serra
- */
- public abstract class AbstractBodyAttraction implements ForceModel {
- /** Suffix for parameter name for attraction coefficient enabling Jacobian processing. */
- public static final String ATTRACTION_COEFFICIENT_SUFFIX = " attraction coefficient";
- /** Central attraction scaling factor.
- * <p>
- * We use a power of 2 to avoid numeric noise introduction
- * in the multiplications/divisions sequences.
- * </p>
- */
- private static final double MU_SCALE = FastMath.scalb(1.0, 32);
- /** The body to consider. */
- private final CelestialBody body;
- /** Drivers for body attraction coefficient. */
- private final ParameterDriver gmParameterDriver;
- /** Simple constructor.
- * @param body the third body to consider
- */
- protected AbstractBodyAttraction(final CelestialBody body) {
- this.body = body;
- this.gmParameterDriver = new ParameterDriver(body.getName() + ATTRACTION_COEFFICIENT_SUFFIX,
- body.getGM(), MU_SCALE, 0.0, Double.POSITIVE_INFINITY);
- }
- /** Getter for the body's name.
- * @return the body's name
- */
- public String getBodyName() {
- return body.getName();
- }
- /** Protected getter for the body.
- * @return the third body considered
- */
- protected CelestialBody getBody() {
- return body;
- }
- /** {@inheritDoc} */
- @Override
- public boolean dependsOnPositionOnly() {
- return true;
- }
- /** {@inheritDoc} */
- @Override
- public List<ParameterDriver> getParametersDrivers() {
- return Collections.singletonList(gmParameterDriver);
- }
- }