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  
22  /** IRNSS time scale (also called IRNWT for IRNSS NetWork Time).
23   * <p>By convention, TIRNSS = TAI - 19 s.</p>
24   * <p>This is intended to be accessed thanks to {@link TimeScales},
25   * so there is no public constructor.</p>
26   * @author Luc Maisonobe
27   * @see AbsoluteDate
28   */
29  public class IRNSSScale implements TimeScale {
30  
31      /** Serializable UID. */
32      private static final long serialVersionUID = 20180323L;
33  
34      /** Offset from TAI. */
35      private static final double OFFSET = -19;
36  
37      /** Package private constructor for the factory.
38       */
39      IRNSSScale() {
40      }
41  
42      /** {@inheritDoc} */
43      @Override
44      public double offsetFromTAI(final AbsoluteDate date) {
45          return OFFSET;
46      }
47  
48      /** {@inheritDoc} */
49      @Override
50      public <T extends CalculusFieldElement<T>> T offsetFromTAI(final FieldAbsoluteDate<T> date) {
51          return date.getField().getZero().add(OFFSET);
52      }
53  
54      /** {@inheritDoc} */
55      @Override
56      public double offsetToTAI(final DateComponents date, final TimeComponents time) {
57          return -OFFSET;
58      }
59  
60      /** {@inheritDoc} */
61      public String getName() {
62          return "IRNSS";
63      }
64  
65      /** {@inheritDoc} */
66      public String toString() {
67          return getName();
68      }
69  
70  }