1   /* Copyright 2002-2022 CS GROUP
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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
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9    *   http://www.apache.org/licenses/LICENSE-2.0
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11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
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14   * See the License for the specific language governing permissions and
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17  package org.orekit.estimation.measurements.modifiers;
18  
19  import org.hipparchus.geometry.euclidean.threed.Vector3D;
20  import org.junit.Assert;
21  import org.junit.Before;
22  import org.junit.Test;
23  import org.orekit.Utils;
24  import org.orekit.estimation.measurements.EstimatedMeasurement;
25  import org.orekit.estimation.measurements.EstimationModifier;
26  import org.orekit.estimation.measurements.InterSatellitesRange;
27  import org.orekit.estimation.measurements.ObservableSatellite;
28  import org.orekit.propagation.SpacecraftState;
29  import org.orekit.propagation.analytical.tle.TLE;
30  import org.orekit.propagation.analytical.tle.TLEPropagator;
31  import org.orekit.time.AbsoluteDate;
32  import org.orekit.time.TimeScalesFactory;
33  
34  public class RelativisticClockInterSatellitesRangeModifierTest {
35  
36      /** Date. */
37      private static AbsoluteDate date;
38  
39      /** Spacecraft states. */
40      private static SpacecraftState[] states;
41  
42      @Test
43      public void testRelativisticClockCorrection() {
44  
45          // Measurement
46          final InterSatellitesRange range = new InterSatellitesRange(new ObservableSatellite(0), new ObservableSatellite(1),
47                                                                      false, date,
48                                                                      Vector3D.distance(states[0].getPVCoordinates().getPosition(),
49                                                                                        states[1].getPVCoordinates().getPosition()),
50                                                                      1.0, 1.0);
51  
52          // Inter-satellites range before applying the modifier
53          final EstimatedMeasurement<InterSatellitesRange> estimatedBefore = range.estimate(0, 0, states);
54  
55          // Inter-satellites range before applying the modifier
56          final EstimationModifier<InterSatellitesRange> modifier = new RelativisticClockInterSatellitesRangeModifier();
57          range.addModifier(modifier);
58          final EstimatedMeasurement<InterSatellitesRange> estimatedAfter = range.estimate(0, 0, states);
59  
60          // Verify
61          Assert.assertEquals(-10.57, estimatedBefore.getEstimatedValue()[0] - estimatedAfter.getEstimatedValue()[0], 1.0e-2);
62          Assert.assertEquals(0, modifier.getParametersDrivers().size());
63  
64      }
65  
66      @Before
67      public void setUp() {
68          // Data root
69          Utils.setDataRoot("regular-data");
70  
71          // Date
72          date = new AbsoluteDate("2004-01-13T00:00:00.000", TimeScalesFactory.getUTC());
73  
74          // Spacecraft states
75          states = new SpacecraftState[2];
76          final TLE local = new TLE("1 27642U 03002A   04013.91734903  .00000108  00000-0  12227-4 0  3621",
77                                    "2 27642  93.9970   6.8623 0003169  80.1383 280.0205 14.90871424 54508");
78          final TLE remote = new TLE("1 20061U 89044A   04013.44391333  .00000095  00000-0  10000-3 0  3242",
79                                     "2 20061  53.4233 172.2072 0234017 261.4179  95.8975  2.00577231106949");
80          states[0] = TLEPropagator.selectExtrapolator(local).propagate(date);
81          states[1] = TLEPropagator.selectExtrapolator(remote).propagate(date);
82      }
83  
84  }