1   /* Copyright 2002-2022 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  
20  
21  import org.junit.Assert;
22  import org.junit.Before;
23  import org.junit.Test;
24  import org.orekit.Utils;
25  import org.orekit.utils.Constants;
26  
27  public class GPSScaleTest {
28  
29      @Test
30      public void testT0() {
31          TimeScale scale = TimeScalesFactory.getGPS();
32          Assert.assertEquals("GPS", scale.toString());
33          AbsoluteDate t0 =
34              new AbsoluteDate(new DateComponents(1980, 1, 6), TimeComponents.H00, scale);
35          Assert.assertEquals(AbsoluteDate.GPS_EPOCH, t0);
36      }
37  
38      @Test
39      public void testArbitrary() {
40          AbsoluteDate tGPS =
41              new AbsoluteDate(new DateComponents(1999, 3, 4), TimeComponents.H00, TimeScalesFactory.getGPS());
42          AbsoluteDate tUTC =
43              new AbsoluteDate(new DateComponents(1999, 3, 3), new TimeComponents(23, 59, 47),
44                               TimeScalesFactory.getUTC());
45          Assert.assertEquals(tUTC, tGPS);
46      }
47  
48      @Test
49      public void testConstant() {
50          TimeScale scale = TimeScalesFactory.getGPS();
51          double reference = scale.offsetFromTAI(AbsoluteDate.J2000_EPOCH);
52          for (double dt = -10000; dt < 10000; dt += 123.456789) {
53              AbsoluteDate date = AbsoluteDate.J2000_EPOCH.shiftedBy(dt * Constants.JULIAN_DAY);
54              Assert.assertEquals(reference, scale.offsetFromTAI(date), 1.0e-15);
55          }
56      }
57  
58      @Test
59      public void testSymmetry() {
60          TimeScale scale = TimeScalesFactory.getGPS();
61          for (double dt = -10000; dt < 10000; dt += 123.456789) {
62              AbsoluteDate date = AbsoluteDate.J2000_EPOCH.shiftedBy(dt * Constants.JULIAN_DAY);
63              double dt1 = scale.offsetFromTAI(date);
64              DateTimeComponents components = date.getComponents(scale);
65              double dt2 = scale.offsetToTAI(components.getDate(), components.getTime());
66              Assert.assertEquals( 0.0, dt1 + dt2, 1.0e-10);
67          }
68      }
69  
70      @Test
71      public void testDuringLeap() {
72          final TimeScale utc   = TimeScalesFactory.getUTC();
73          final TimeScale scale = TimeScalesFactory.getGPS();
74          final AbsoluteDate before = new AbsoluteDate(new DateComponents(1983, 06, 30),
75                                                       new TimeComponents(23, 59, 59),
76                                                       utc);
77          final AbsoluteDate during = before.shiftedBy(1.25);
78          Assert.assertEquals(61, utc.minuteDuration(during));
79          Assert.assertEquals(1.0, utc.getLeap(during), 1.0e-10);
80          Assert.assertEquals(60, scale.minuteDuration(during));
81          Assert.assertEquals(0.0, scale.getLeap(during), 1.0e-10);
82      }
83  
84      @Before
85      public void setUp() {
86          Utils.setDataRoot("regular-data");
87      }
88  
89  }