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17  package org.orekit.time;
18  
19  import org.junit.jupiter.api.Assertions;
20  import org.junit.jupiter.api.BeforeEach;
21  import org.junit.jupiter.api.Test;
22  import org.orekit.Utils;
23  import org.orekit.frames.ITRFVersion;
24  import org.orekit.utils.Constants;
25  import org.orekit.utils.IERSConventions;
26  
27  
28  public class TCGScaleTest {
29  
30      @Test
31      public void testRatio() {
32          TimeScale scale = TimeScalesFactory.getTCG();
33          Assertions.assertEquals("TCG", scale.toString());
34          final double dtTT = 1e6;
35          final AbsoluteDate t1 = AbsoluteDate.J2000_EPOCH;
36          final AbsoluteDate t2 = t1.shiftedBy(dtTT);
37          final double dtTCG = dtTT + scale.offsetFromTAI(t2).subtract(scale.offsetFromTAI(t1)).toDouble();
38          Assertions.assertEquals(1 - 6.969290134e-10, dtTT / dtTCG, 1.0e-15);
39      }
40  
41      @Test
42      public void testSymmetry() {
43          TimeScale scale = TimeScalesFactory.getTCG();
44          for (double dt = -10000; dt < 10000; dt += 123.456789) {
45              AbsoluteDate date = AbsoluteDate.J2000_EPOCH.shiftedBy(dt * Constants.JULIAN_DAY);
46              double dt1 = scale.offsetFromTAI(date).toDouble();
47              DateTimeComponents components = date.getComponents(scale);
48              double dt2 = scale.offsetToTAI(components.getDate(), components.getTime()).toDouble();
49              Assertions.assertEquals( 0.0, dt1 + dt2, 1.0e-10);
50          }
51      }
52  
53      @Test
54      public void testDuringLeap() {
55          final TimeScale utc   = TimeScalesFactory.getUTC();
56          final TimeScale scale = TimeScalesFactory.getTCG();
57          final AbsoluteDate before = new AbsoluteDate(new DateComponents(1983, 6, 30),
58                                                       new TimeComponents(23, 59, 59),
59                                                       utc);
60          final AbsoluteDate during = before.shiftedBy(1.25);
61          Assertions.assertEquals(61, utc.minuteDuration(during));
62          Assertions.assertEquals(1.0, utc.getLeap(during).toDouble(), 1.0e-10);
63          Assertions.assertEquals(60, scale.minuteDuration(during));
64          Assertions.assertEquals(0.0, scale.getLeap(during).toDouble(), 1.0e-10);
65      }
66  
67      @Test
68      public void testReference() {
69          DateComponents referenceDate = new DateComponents(1977, 1, 1);
70          TimeComponents thirtyTwo     = new TimeComponents(0, 0, new TimeOffset(32L, 184000000000000000L));
71          AbsoluteDate   ttRef         = new AbsoluteDate(referenceDate, thirtyTwo, TimeScalesFactory.getTT());
72          AbsoluteDate   tcgRef        = new AbsoluteDate(referenceDate, thirtyTwo, TimeScalesFactory.getTCG());
73          AbsoluteDate   taiRef        = new AbsoluteDate(referenceDate, TimeComponents.H00, TimeScalesFactory.getTAI());
74          AbsoluteDate   utcRef        = new AbsoluteDate(new DateComponents(1976, 12, 31),
75                                                          new TimeComponents(23, 59, 45),
76                                                          TimeScalesFactory.getUTC());
77          Assertions.assertEquals(0, ttRef.durationFrom(tcgRef), 1.0e-20);
78          Assertions.assertEquals(0, ttRef.durationFrom(taiRef), 1.0e-20);
79          Assertions.assertEquals(0, ttRef.durationFrom(utcRef), 1.0e-20);
80      }
81  
82      @Test
83      public void testSofa() {
84          TimeScale tt  = TimeScalesFactory.getTT();
85          AbsoluteDate date = new AbsoluteDate(2006, 1, 15, 21, 25, 10.5000096, tt);
86          TimeOffset delta = TimeScalesFactory.getTCG().offsetFromTAI(date).subtract(tt.offsetFromTAI(date));
87          Assertions.assertEquals(Constants.JULIAN_DAY * (0.8924900312508587113 -  0.892482639), delta.toDouble(), 5.0e-10);
88      }
89  
90      @Test
91      public void testAAS06134() {
92  
93          // this reference test has been extracted from the following paper:
94          // Implementation Issues Surrounding the New IAU Reference Systems for Astrodynamics
95          // David A. Vallado, John H. Seago, P. Kenneth Seidelmann
96          // http://www.centerforspace.com/downloads/files/pubs/AAS-06-134.pdf
97          // Note that the dUT1 here is -0.439962, whereas it is -0.4399619 in the book
98          Utils.setLoaders(IERSConventions.IERS_1996,
99                           Utils.buildEOPList(IERSConventions.IERS_1996, ITRFVersion.ITRF_2008, new double[][] {
100                              { 53098, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN },
101                              { 53099, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN },
102                              { 53100, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN },
103                              { 53101, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN },
104                              { 53102, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN },
105                              { 53103, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN },
106                              { 53104, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN },
107                              { 53105, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN }
108                          }));
109         AbsoluteDate date =
110                 new AbsoluteDate(2004, 4, 6, 7, 51, 28.386009, TimeScalesFactory.getUTC());
111         DateTimeComponents components = date.getComponents(TimeScalesFactory.getTCG());
112         Assertions.assertEquals(2004,            components.getDate().getYear());
113         Assertions.assertEquals(   4,            components.getDate().getMonth());
114         Assertions.assertEquals(   6,            components.getDate().getDay());
115         Assertions.assertEquals(   7,            components.getTime().getHour());
116         Assertions.assertEquals(  52,            components.getTime().getMinute());
117         Assertions.assertEquals(  33.1695861742, components.getTime().getSecond(), 1.0e-10);
118 
119     }
120 
121     @BeforeEach
122     public void setUp() {
123         Utils.setDataRoot("regular-data");
124     }
125 
126 }