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  
26  /**
27   * Class defining the Keplerian contributions in the adjoint equations for Cartesian coordinates.
28   * If present, then the propagator should also include the Newtonian attraction of a central body.
29   * @author Romain Serra
30   * @see CartesianAdjointEquationTerm
31   * @see org.orekit.forces.gravity.NewtonianAttraction
32   * @since 12.2
33   */
34  public class CartesianAdjointKeplerianTerm extends AbstractCartesianAdjointNewtonianTerm {
35  
36      /**
37       * Constructor.
38       * @param mu central body gravitational parameter
39       */
40      public CartesianAdjointKeplerianTerm(final double mu) {
41          super(mu);
42      }
43  
44      /** {@inheritDoc} */
45      @Override
46      public double[] getPositionAdjointContribution(final AbsoluteDate date, final double[] stateVariables,
47                                                     final double[] adjointVariables, final Frame frame) {
48          return getNewtonianVelocityAdjointContribution(stateVariables, adjointVariables);
49      }
50  
51      /** {@inheritDoc} */
52      @Override
53      public <T extends CalculusFieldElement<T>> T[] getPositionAdjointFieldContribution(final FieldAbsoluteDate<T> date,
54                                                                                         final T[] stateVariables,
55                                                                                         final T[] adjointVariables,
56                                                                                         final Frame frame) {
57          return getFieldNewtonianVelocityAdjointContribution(stateVariables, adjointVariables);
58      }
59  
60      /** {@inheritDoc} */
61      @Override
62      protected Vector3D getAcceleration(final AbsoluteDate date, final double[] stateVariables,
63                                         final Frame frame) {
64          return getNewtonianAcceleration(stateVariables);
65      }
66  
67      /** {@inheritDoc} */
68      @Override
69      protected <T extends CalculusFieldElement<T>> FieldVector3D<T> getFieldAcceleration(final FieldAbsoluteDate<T> date,
70                                                                                          final T[] stateVariables,
71                                                                                          final Frame frame) {
72          return getFieldNewtonianAcceleration(stateVariables);
73      }
74  }