1   /* Copyright 2022-2025 Romain Serra
2    * Licensed to CS GROUP (CS) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * CS licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *   http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.orekit.control.indirect.adjoint;
18  
19  import org.hipparchus.CalculusFieldElement;
20  import org.hipparchus.geometry.euclidean.threed.FieldVector3D;
21  import org.hipparchus.geometry.euclidean.threed.Vector3D;
22  import org.orekit.frames.Frame;
23  import org.orekit.time.AbsoluteDate;
24  import org.orekit.time.FieldAbsoluteDate;
25  import org.orekit.utils.ExtendedPositionProvider;
26  
27  /**
28   * Class defining the contributions of a point-mass, single body gravity in the adjoint equations for Cartesian coordinates.
29   * If present, then the propagator should also include the Newtonian attraction of a body.
30   * This is similar to {@link CartesianAdjointKeplerianTerm} but with the body not necessarily a central one.
31   * @author Romain Serra
32   * @see CartesianAdjointEquationTerm
33   * @see org.orekit.forces.gravity.SingleBodyAbsoluteAttraction
34   * @since 12.2
35   */
36  public class CartesianAdjointSingleBodyTerm extends AbstractCartesianAdjointNonCentralBodyTerm {
37  
38      /**
39       * Constructor.
40       * @param mu body gravitational parameter.
41       * @param bodyPositionProvider body position provider
42       */
43      public CartesianAdjointSingleBodyTerm(final double mu, final ExtendedPositionProvider bodyPositionProvider) {
44          super(mu, bodyPositionProvider);
45      }
46  
47      /** {@inheritDoc} */
48      @Override
49      public Vector3D getAcceleration(final AbsoluteDate date, final double[] stateVariables,
50                                      final Frame frame) {
51          final double[] relativePosition = formRelativePosition(date, stateVariables, frame);
52          return getNewtonianAcceleration(relativePosition);
53      }
54  
55      /** {@inheritDoc} */
56      @Override
57      public <T extends CalculusFieldElement<T>> FieldVector3D<T> getFieldAcceleration(final FieldAbsoluteDate<T> date,
58                                                                                       final T[] stateVariables,
59                                                                                       final Frame frame) {
60          final T[] relativePosition = formFieldRelativePosition(date, stateVariables, frame);
61          return getFieldNewtonianAcceleration(relativePosition);
62      }
63  }