1   /* Copyright 2002-2025 CS GROUP
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.data;
18  
19  import org.hipparchus.CalculusFieldElement;
20  
21  /** Class for tide terms.
22   * <p>
23   * BEWARE! For consistency with all the other Poisson series terms,
24   * the elements in γ, l, l', F, D and Ω are ADDED together to compute
25   * the argument of the term. In classical tides series, the computed
26   * argument is cGamma * γ - (cL * l + cLPrime * l' + cF * F + cD * D
27   * + cOmega * Ω). So at parsing time, the signs of cL, cLPrime, cF,
28   * cD and cOmega must already have been reversed so the addition
29   * performed here will work. This is done automatically when the
30   * parser has been configured with a call to {@link
31   * PoissonSeriesParser#withDoodson(int, int)} as the relationship
32   * between the Doodson arguments and the traditional Delaunay
33   * arguments ensures the proper sign is known.
34   * </p>
35   * @author Luc Maisonobe
36   */
37  class TideTerm extends SeriesTerm {
38  
39      /** Coefficient for γ = GMST + π tide parameter. */
40      private final int cGamma;
41  
42      /** Coefficient for mean anomaly of the Moon. */
43      private final int cL;
44  
45      /** Coefficient for mean anomaly of the Sun. */
46      private final int cLPrime;
47  
48      /** Coefficient for L - Ω where L is the mean longitude of the Moon. */
49      private final int cF;
50  
51      /** Coefficient for mean elongation of the Moon from the Sun. */
52      private final int cD;
53  
54      /** Coefficient for mean longitude of the ascending node of the Moon. */
55      private final int cOmega;
56  
57      /** Build a tide term for nutation series.
58       * @param cGamma coefficient for γ = GMST + π tide parameter
59       * @param cL coefficient for mean anomaly of the Moon
60       * @param cLPrime coefficient for mean anomaly of the Sun
61       * @param cF coefficient for L - Ω where L is the mean longitude of the Moon
62       * @param cD coefficient for mean elongation of the Moon from the Sun
63       * @param cOmega coefficient for mean longitude of the ascending node of the Moon
64       */
65      TideTerm(final int cGamma,
66               final int cL, final int cLPrime, final int cF, final int cD, final int cOmega) {
67          this.cGamma  = cGamma;
68          this.cL      = cL;
69          this.cLPrime = cLPrime;
70          this.cF      = cF;
71          this.cD      = cD;
72          this.cOmega  = cOmega;
73      }
74  
75      /** {@inheritDoc} */
76      protected double argument(final BodiesElements elements) {
77          return cGamma * elements.getGamma() +
78                 cL * elements.getL() + cLPrime * elements.getLPrime() + cF * elements.getF() +
79                 cD * elements.getD() + cOmega * elements.getOmega();
80      }
81  
82      /** {@inheritDoc} */
83      protected double argumentDerivative(final BodiesElements elements) {
84          return cGamma * elements.getGammaDot() +
85                 cL * elements.getLDot() + cLPrime * elements.getLPrimeDot() + cF * elements.getFDot() +
86                 cD * elements.getDDot() + cOmega * elements.getOmegaDot();
87      }
88  
89      /** {@inheritDoc} */
90      protected <T extends CalculusFieldElement<T>> T argument(final FieldBodiesElements<T> elements) {
91          return elements.getGamma().multiply(cGamma).
92                 add(elements.getL().multiply(cL)).
93                 add(elements.getLPrime().multiply(cLPrime)).
94                 add(elements.getF().multiply(cF)).
95                 add(elements.getD().multiply(cD)).
96                 add(elements.getOmega().multiply(cOmega));
97      }
98  
99      /** {@inheritDoc} */
100     protected <T extends CalculusFieldElement<T>> T argumentDerivative(final FieldBodiesElements<T> elements) {
101         return elements.getGammaDot().multiply(cGamma).
102                add(elements.getLDot().multiply(cL)).
103                add(elements.getLPrimeDot().multiply(cLPrime)).
104                add(elements.getFDot().multiply(cF)).
105                add(elements.getDDot().multiply(cD)).
106                add(elements.getOmegaDot().multiply(cOmega));
107     }
108 
109 }