1   /* Copyright 2002-2023 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.time;
18  
19  import org.hipparchus.CalculusFieldElement;
20  
21  /** QZSS time scale.
22   * <p>By convention, TQZSS = TAI - 19 s.</p>
23   * <p>The time scale is defined in <a
24   * href="http://qzss.go.jp/en/technical/download/pdf/ps-is-qzss/is-qzss-pnt-003.pdf?t=1549268771755">
25   * Quasi-Zenith Satellite System Navigation Service - Interface Specification for QZSS</a> version 1.6, 2014.
26   * </p>
27   * <p>This is intended to be accessed thanks to {@link TimeScales},
28   * so there is no public constructor.</p>
29   * @author Luc Maisonobe
30   * @see AbsoluteDate
31   */
32  public class QZSSScale implements TimeScale {
33  
34      /** Serializable UID. */
35      private static final long serialVersionUID = 20131209L;
36  
37      /** Offset from TAI. */
38      private static final double OFFSET = -19;
39  
40      /** Package private constructor for the factory.
41       */
42      QZSSScale() {
43      }
44  
45      /** {@inheritDoc} */
46      @Override
47      public double offsetFromTAI(final AbsoluteDate date) {
48          return OFFSET;
49      }
50  
51      /** {@inheritDoc} */
52      @Override
53      public <T extends CalculusFieldElement<T>> T offsetFromTAI(final FieldAbsoluteDate<T> date) {
54          return date.getField().getZero().add(OFFSET);
55      }
56  
57      /** {@inheritDoc} */
58      @Override
59      public double offsetToTAI(final DateComponents date, final TimeComponents time) {
60          return -OFFSET;
61      }
62  
63      /** {@inheritDoc} */
64      public String getName() {
65          return "QZSS";
66      }
67  
68      /** {@inheritDoc} */
69      public String toString() {
70          return getName();
71      }
72  
73  }