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.bodies;
18  
19  import java.io.Serializable;
20  
21  import org.hipparchus.CalculusFieldElement;
22  import org.hipparchus.geometry.euclidean.threed.FieldVector3D;
23  import org.hipparchus.geometry.euclidean.threed.Vector3D;
24  import org.orekit.time.AbsoluteDate;
25  import org.orekit.time.FieldAbsoluteDate;
26  
27  /** Interface for IAU pole and prime meridian orientations.
28   * <p>
29   * This interface defines methods compliant with the report of the
30   * IAU/IAG Working Group on Cartographic Coordinates and Rotational
31   * Elements of the Planets and Satellites (WGCCRE). These definitions
32   * are common for all recent versions of this report published every
33   * three years.
34   * </p>
35   * <p>
36   * The precise values of pole direction and W angle coefficients may vary
37   * from publication year as models are adjusted. The latest value of
38   * constants for implementing this interface can be found in the <a
39   * href="http://astrogeology.usgs.gov/Projects/WGCCRE/">working group
40   * site</a>.
41   * </p>
42   * @see CelestialBodies
43   * @author Luc Maisonobe
44   */
45  public interface IAUPole extends Serializable {
46  
47      /** Get the body North pole direction in ICRF frame.
48       * @param date current date
49       * @return body North pole direction in ICRF frame
50       */
51      Vector3D getPole(AbsoluteDate date);
52  
53      /** Get the body North pole direction in ICRF frame.
54       * @param date current date
55       * @param <T> type of the field elements
56       * @return body North pole direction in ICRF frame
57       * @since 9.0
58       */
59      <T extends CalculusFieldElement<T>> FieldVector3D<T> getPole(FieldAbsoluteDate<T> date);
60  
61      /** Get the body Q Node direction in ICRF frame.
62       * @param date current date
63       * @return body Q Node direction in ICRF frame
64       * @since 9.1
65       */
66      default Vector3D getNode(final AbsoluteDate date) {
67          return Vector3D.crossProduct(Vector3D.PLUS_K, getPole(date));
68      }
69  
70      /** Get the body Q Node direction in ICRF frame.
71       * @param date current date
72       * @param <T> type of the field elements
73       * @return body Q Node direction in ICRF frame
74       * @since 9.1
75       */
76      default <T extends CalculusFieldElement<T>> FieldVector3D<T> getNode(final FieldAbsoluteDate<T> date) {
77          return FieldVector3D.crossProduct(FieldVector3D.getPlusK(date.getField()), getPole(date));
78      }
79  
80      /** Get the prime meridian angle.
81       * <p>
82       * The prime meridian angle is the angle between the Q node and the
83       * prime meridian. represents the body rotation.
84       * </p>
85       * @param date current date
86       * @return prime meridian vector
87       */
88      double getPrimeMeridianAngle(AbsoluteDate date);
89  
90      /** Get the prime meridian angle.
91       * <p>
92       * The prime meridian angle is the angle between the Q node and the
93       * prime meridian. represents the body rotation.
94       * </p>
95       * @param date current date
96       * @param <T> type of the field elements
97       * @return prime meridian vector
98       * @since 9.0
99       */
100     <T extends CalculusFieldElement<T>> T getPrimeMeridianAngle(FieldAbsoluteDate<T> date);
101 
102 }