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  
18  package org.orekit.files.ccsds.ndm.odm;
19  
20  import java.io.IOException;
21  
22  import org.hipparchus.linear.RealMatrix;
23  import org.orekit.files.ccsds.definitions.Units;
24  import org.orekit.files.ccsds.section.AbstractWriter;
25  import org.orekit.files.ccsds.utils.generation.Generator;
26  
27  /** Writer for covariance matrix data.
28   * @author Luc Maisonobe
29   * @since 11.0
30   */
31  public class CartesianCovarianceWriter extends AbstractWriter {
32  
33      /** Covariance matrix block. */
34      private final CartesianCovariance covariance;
35  
36      /** Create a writer.
37       * @param xmlTag name of the XML tag surrounding the section
38       * @param kvnTag name of the KVN tag surrounding the section (may be null)
39       * @param covariance covariance matrix to write
40       */
41      public CartesianCovarianceWriter(final String xmlTag, final String kvnTag,
42                                        final CartesianCovariance covariance) {
43          super(xmlTag, kvnTag);
44          this.covariance = covariance;
45      }
46  
47      /** {@inheritDoc} */
48      @Override
49      protected void writeContent(final Generator generator) throws IOException {
50  
51          final RealMatrix matrix = covariance.getCovarianceMatrix();
52  
53          // covariance block
54          generator.writeComments(covariance.getComments());
55          // note that there are no epochs in the OPM/OMM covariance matrices (but there are epochs in OEM covariance matrices)
56          generator.writeEntry(CartesianCovarianceKey.COV_REF_FRAME.name(), covariance.getReferenceFrame().getName(), null,             false);
57          generator.writeEntry(CartesianCovarianceKey.CX_X.name(),          matrix.getEntry(0, 0),                    Units.KM2,        true);
58          generator.writeEntry(CartesianCovarianceKey.CY_X.name(),          matrix.getEntry(1, 0),                    Units.KM2,        true);
59          generator.writeEntry(CartesianCovarianceKey.CY_Y.name(),          matrix.getEntry(1, 1),                    Units.KM2,        true);
60          generator.writeEntry(CartesianCovarianceKey.CZ_X.name(),          matrix.getEntry(2, 0),                    Units.KM2,        true);
61          generator.writeEntry(CartesianCovarianceKey.CZ_Y.name(),          matrix.getEntry(2, 1),                    Units.KM2,        true);
62          generator.writeEntry(CartesianCovarianceKey.CZ_Z.name(),          matrix.getEntry(2, 2),                    Units.KM2,        true);
63          generator.writeEntry(CartesianCovarianceKey.CX_DOT_X.name(),      matrix.getEntry(3, 0),                    Units.KM2_PER_S,  true);
64          generator.writeEntry(CartesianCovarianceKey.CX_DOT_Y.name(),      matrix.getEntry(3, 1),                    Units.KM2_PER_S,  true);
65          generator.writeEntry(CartesianCovarianceKey.CX_DOT_Z.name(),      matrix.getEntry(3, 2),                    Units.KM2_PER_S,  true);
66          generator.writeEntry(CartesianCovarianceKey.CX_DOT_X_DOT.name(),  matrix.getEntry(3, 3),                    Units.KM2_PER_S2, true);
67          generator.writeEntry(CartesianCovarianceKey.CY_DOT_X.name(),      matrix.getEntry(4, 0),                    Units.KM2_PER_S,  true);
68          generator.writeEntry(CartesianCovarianceKey.CY_DOT_Y.name(),      matrix.getEntry(4, 1),                    Units.KM2_PER_S,  true);
69          generator.writeEntry(CartesianCovarianceKey.CY_DOT_Z.name(),      matrix.getEntry(4, 2),                    Units.KM2_PER_S,  true);
70          generator.writeEntry(CartesianCovarianceKey.CY_DOT_X_DOT.name(),  matrix.getEntry(4, 3),                    Units.KM2_PER_S2, true);
71          generator.writeEntry(CartesianCovarianceKey.CY_DOT_Y_DOT.name(),  matrix.getEntry(4, 4),                    Units.KM2_PER_S2, true);
72          generator.writeEntry(CartesianCovarianceKey.CZ_DOT_X.name(),      matrix.getEntry(5, 0),                    Units.KM2_PER_S,  true);
73          generator.writeEntry(CartesianCovarianceKey.CZ_DOT_Y.name(),      matrix.getEntry(5, 1),                    Units.KM2_PER_S,  true);
74          generator.writeEntry(CartesianCovarianceKey.CZ_DOT_Z.name(),      matrix.getEntry(5, 2),                    Units.KM2_PER_S,  true);
75          generator.writeEntry(CartesianCovarianceKey.CZ_DOT_X_DOT.name(),  matrix.getEntry(5, 3),                    Units.KM2_PER_S2, true);
76          generator.writeEntry(CartesianCovarianceKey.CZ_DOT_Y_DOT.name(),  matrix.getEntry(5, 4),                    Units.KM2_PER_S2, true);
77          generator.writeEntry(CartesianCovarianceKey.CZ_DOT_Z_DOT.name(),  matrix.getEntry(5, 5),                    Units.KM2_PER_S2, true);
78  
79      }
80  
81  }