1   /* Copyright 2022-2025 Thales Alenia Space
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.models.earth.displacement;
18  
19  import org.hipparchus.geometry.euclidean.threed.Vector3D;
20  import org.orekit.bodies.GeodeticPoint;
21  import org.orekit.data.BodiesElements;
22  import org.orekit.frames.Frame;
23  import org.orekit.utils.TimeSpanMap;
24  
25  import java.util.List;
26  
27  /** Modeling of displacement of one reference point due to post-seismic effects.
28   * @see <a href="https://itrf.ign.fr/ftp/pub/itrf/itrf2020/ITRF2020-PSD-model-eqs-IGN.pdf">
29   *     ITRF2020P: Equations of post-seismic deformation models</a>
30   * @since 12.1
31   * @author Luc Maisonobe
32   */
33  public class PostSeismicDeformation implements StationDisplacement {
34  
35      /** Base point. */
36      private final GeodeticPoint base;
37  
38      /** PSD corrections. */
39      private final TimeSpanMap<List<PsdCorrection>> corrections;
40  
41      /** Simple constructor.
42       * @param base base point
43       * @param corrections Post-Seismic Deformation corrections
44       */
45      public PostSeismicDeformation(final GeodeticPoint base,
46                                    final TimeSpanMap<List<PsdCorrection>> corrections) {
47          this.base        = base;
48          this.corrections = corrections;
49      }
50  
51      /** {@inheritDoc} */
52      @Override
53      public Vector3D displacement(final BodiesElements elements, final Frame earthFrame, final Vector3D referencePoint) {
54  
55          // initialize displacement with zero correction
56          Vector3D cumulativeCorrection = Vector3D.ZERO;
57  
58          // apply all relevant Post-Seismic Deformation corrections
59          final List<PsdCorrection> correctionsAtDate = corrections.get(elements.getDate());
60          if (correctionsAtDate != null) {
61              for (final PsdCorrection correction : correctionsAtDate) {
62                  cumulativeCorrection = cumulativeCorrection.add(correction.displacement(elements.getDate(), base));
63              }
64          }
65  
66          return cumulativeCorrection;
67  
68      }
69  
70  }