1   /* Copyright 2002-2026 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  
18  package org.orekit.files.ccsds.ndm.odm.oem;
19  
20  import java.util.List;
21  
22  import org.orekit.files.ccsds.ndm.odm.CartesianCovariance;
23  import org.orekit.files.ccsds.section.Segment;
24  import org.orekit.files.general.EphemerisFile;
25  import org.orekit.frames.Frame;
26  import org.orekit.time.AbsoluteDate;
27  import org.orekit.utils.CartesianDerivativesFilter;
28  import org.orekit.utils.TimeStampedPVCoordinates;
29  
30  /** The Ephemerides Blocks class contain metadata, the list of ephemerides data
31   * lines and optional covariance matrices (and their metadata). The reason
32   * for which the ephemerides have been separated into blocks is that the
33   * ephemerides of two different blocks are not suited for interpolation.
34   * @author sports
35   */
36  public class OemSegment extends Segment<OemMetadata, OemData>
37      implements EphemerisFile.EphemerisSegment<TimeStampedPVCoordinates> {
38  
39      /** Gravitational parameter in m³/s². */
40      private final double mu;
41  
42      /** Simple constructor.
43       * @param metadata segment metadata
44       * @param data segment data
45       * @param mu gravitational parameter in m³/s²
46       */
47      public OemSegment(final OemMetadata metadata, final OemData data, final double mu) {
48          super(metadata, data);
49          this.mu = mu;
50      }
51  
52      /** {@inheritDoc} */
53      @Override
54      public double getMu() {
55          return mu;
56      }
57  
58      /** {@inheritDoc} */
59      @Override
60      public List<TimeStampedPVCoordinates> getCoordinates() {
61          return getData().getCoordinates();
62      }
63  
64      /** {@inheritDoc} */
65      @Override
66      public CartesianDerivativesFilter getAvailableDerivatives() {
67          return getData().getAvailableDerivatives();
68      }
69  
70      /** Get an unmodifiable view of Covariance Matrices.
71       * @return unmodifiable view of Covariance Matrices
72       */
73      public List<CartesianCovariance> getCovarianceMatrices() {
74          return getData().getCovarianceMatrices();
75      }
76  
77      /** {@inheritDoc} */
78      @Override
79      public Frame getFrame() {
80          return getMetadata().getFrame();
81      }
82  
83      /** {@inheritDoc} */
84      @Override
85      public AbsoluteDate getStart() {
86          // useable start time overrides start time if it is set
87          final AbsoluteDate start = getMetadata().getUseableStartTime();
88          if (start != null) {
89              return start;
90          } else {
91              return getMetadata().getStartTime();
92          }
93      }
94  
95      /** {@inheritDoc} */
96      @Override
97      public AbsoluteDate getStop() {
98          // useable stop time overrides stop time if it is set
99          final AbsoluteDate stop = getMetadata().getUseableStopTime();
100         if (stop != null) {
101             return stop;
102         } else {
103             return getMetadata().getStopTime();
104         }
105     }
106 
107     /** {@inheritDoc} */
108     @Override
109     public int getInterpolationSamples() {
110         // From the standard it is not entirely clear how to interpret the degree.
111         return getMetadata().getInterpolationDegree() + 1;
112     }
113 
114 }