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17  package org.orekit.estimation.measurements.modifiers;
18  
19  import java.util.List;
20  
21  import org.hipparchus.geometry.euclidean.threed.Vector3D;
22  import org.junit.jupiter.api.Assertions;
23  import org.junit.jupiter.api.Test;
24  import org.orekit.attitudes.LofOffset;
25  import org.orekit.estimation.Context;
26  import org.orekit.estimation.EstimationTestUtils;
27  import org.orekit.estimation.measurements.EstimatedMeasurementBase;
28  import org.orekit.estimation.measurements.ObservedMeasurement;
29  import org.orekit.estimation.measurements.gnss.OneWayGNSSPhase;
30  import org.orekit.estimation.measurements.gnss.OneWayGNSSPhaseCreator;
31  import org.orekit.frames.LOFType;
32  import org.orekit.gnss.PredefinedGnssSignal;
33  import org.orekit.gnss.RadioWave;
34  import org.orekit.orbits.CartesianOrbit;
35  import org.orekit.orbits.Orbit;
36  import org.orekit.orbits.OrbitType;
37  import org.orekit.orbits.PositionAngleType;
38  import org.orekit.propagation.BoundedPropagator;
39  import org.orekit.propagation.EphemerisGenerator;
40  import org.orekit.propagation.Propagator;
41  import org.orekit.propagation.SpacecraftState;
42  import org.orekit.propagation.conversion.NumericalPropagatorBuilder;
43  import org.orekit.utils.TimeStampedPVCoordinates;
44  
45  
46  public class OnBoardAntennaOneWayGNSSPhaseModifierTest {
47  
48      private static final RadioWave RADIO_WAVE = PredefinedGnssSignal.G01;
49  
50      @Test
51      public void testPreliminary() {
52  
53          Context context = EstimationTestUtils.eccentricContext("regular-data:potential:tides");
54  
55          final NumericalPropagatorBuilder propagatorBuilder =
56                          context.createBuilder(OrbitType.KEPLERIAN, PositionAngleType.TRUE, true,
57                                                1.0e-6, 60.0, 0.001);
58          propagatorBuilder.setAttitudeProvider(new LofOffset(propagatorBuilder.getFrame(), LOFType.LVLH));
59  
60          // create perfect one-way GNSS phase measurements without antenna offset
61          final TimeStampedPVCoordinates original = context.initialOrbit.getPVCoordinates();
62          final Orbit closeOrbit = new CartesianOrbit(new TimeStampedPVCoordinates(context.initialOrbit.getDate(),
63                                                                                   original.getPosition().add(new Vector3D(1000, 2000, 3000)),
64                                                                                   original.getVelocity().add(new Vector3D(-0.03, 0.01, 0.02))),
65                                                      context.initialOrbit.getFrame(),
66                                                      context.initialOrbit.getMu());
67          final Propagator closePropagator = EstimationTestUtils.createPropagator(closeOrbit,
68                                                                                  propagatorBuilder);
69          final EphemerisGenerator generator = closePropagator.getEphemerisGenerator();
70          closePropagator.propagate(context.initialOrbit.getDate().shiftedBy(3.5 * closeOrbit.getKeplerianPeriod()));
71          final BoundedPropagator ephemeris = generator.getGeneratedEphemeris();
72          final Propagator p1 = EstimationTestUtils.createPropagator(context.initialOrbit,
73                                                                             propagatorBuilder);
74          final int    ambiguity         = 0;
75          final double localClockOffset  = 0.137e-6;
76          final double remoteClockOffset = 469.0e-6;
77          final List<ObservedMeasurement<?>> spacecraftCenteredMeasurements =
78                          EstimationTestUtils.createMeasurements(p1,
79                                                                 new OneWayGNSSPhaseCreator(ephemeris,
80                                                                                            "remote", RADIO_WAVE,
81                                                                                            ambiguity,
82                                                                                            localClockOffset,
83                                                                                            remoteClockOffset,
84                                                                                            Vector3D.ZERO,
85                                                                                            Vector3D.ZERO),
86                                                                 1.0, 3.0, 300.0);
87  
88          // create perfect one-way GNSS phase measurements with antenna offset
89          final double xOffset1 = -2.5;
90          final double yOffset2 =  0.8;
91          final Propagator p2 = EstimationTestUtils.createPropagator(context.initialOrbit,
92                                                                     propagatorBuilder);
93          final List<ObservedMeasurement<?>> antennaCenteredMeasurements =
94                          EstimationTestUtils.createMeasurements(p2,
95                                                                 new OneWayGNSSPhaseCreator(ephemeris,
96                                                                                            "remote", RADIO_WAVE,
97                                                                                            ambiguity,
98                                                                                            localClockOffset,
99                                                                                            remoteClockOffset,
100                                                                                           new Vector3D(xOffset1, 0, 0),
101                                                                                           new Vector3D(0, yOffset2, 0)),
102                                                                1.0, 3.0, 300.0);
103 
104         for (int i = 0; i < spacecraftCenteredMeasurements.size(); ++i) {
105             OneWayGNSSPhase sr = (OneWayGNSSPhase) spacecraftCenteredMeasurements.get(i);
106             OneWayGNSSPhase ar = (OneWayGNSSPhase) antennaCenteredMeasurements.get(i);
107             Assertions.assertEquals(0.0, sr.getDate().durationFrom(ar.getDate()), 2.0e-8);
108             Assertions.assertTrue((ar.getObservedValue()[0] - sr.getObservedValue()[0]) * RADIO_WAVE.getWavelength() >= -1.0);
109             Assertions.assertTrue((ar.getObservedValue()[0] - sr.getObservedValue()[0]) * RADIO_WAVE.getWavelength() <= -0.36);
110         }
111     }
112 
113     @Test
114     public void testEffect() {
115 
116         Context context = EstimationTestUtils.eccentricContext("regular-data:potential:tides");
117 
118         final NumericalPropagatorBuilder propagatorBuilder =
119                         context.createBuilder(OrbitType.KEPLERIAN, PositionAngleType.TRUE, true,
120                                               1.0e-6, 60.0, 0.001);
121         propagatorBuilder.setAttitudeProvider(new LofOffset(propagatorBuilder.getFrame(), LOFType.LVLH));
122 
123         // create perfect one-way GNSS phase phase measurements without antenna offset
124         final TimeStampedPVCoordinates original = context.initialOrbit.getPVCoordinates();
125         final Orbit closeOrbit = new CartesianOrbit(new TimeStampedPVCoordinates(context.initialOrbit.getDate(),
126                                                                                  original.getPosition().add(new Vector3D(1000, 2000, 3000)),
127                                                                                  original.getVelocity().add(new Vector3D(-0.03, 0.01, 0.02))),
128                                                     context.initialOrbit.getFrame(),
129                                                     context.initialOrbit.getMu());
130         final Propagator closePropagator = EstimationTestUtils.createPropagator(closeOrbit,
131                                                                                 propagatorBuilder);
132         final EphemerisGenerator generator = closePropagator.getEphemerisGenerator();
133         closePropagator.propagate(context.initialOrbit.getDate().shiftedBy(10.0 * closeOrbit.getKeplerianPeriod()));
134         final BoundedPropagator ephemeris = generator.getGeneratedEphemeris();
135         final Propagator p1 = EstimationTestUtils.createPropagator(context.initialOrbit,
136                                                                            propagatorBuilder);
137         final int    ambiguity         = 0;
138         final double localClockOffset  = 0.137e-6;
139         final double remoteClockOffset = 469.0e-6;
140         final List<ObservedMeasurement<?>> spacecraftCenteredMeasurements =
141                         EstimationTestUtils.createMeasurements(p1,
142                                                                new OneWayGNSSPhaseCreator(ephemeris,
143                                                                                           "remote", RADIO_WAVE,
144                                                                                           ambiguity,
145                                                                                           localClockOffset,
146                                                                                           remoteClockOffset),
147                                                                1.0, 3.0, 300.0);
148 
149         // create perfect one-way GNSS phase measurements with antenna offset
150         final Vector3D apc1 = new Vector3D(-2.5, 0.0, 0);
151         final Vector3D apc2 = new Vector3D( 0.0, 0.8, 0);
152         final Propagator p2 = EstimationTestUtils.createPropagator(context.initialOrbit,
153                                                                    propagatorBuilder);
154         final List<ObservedMeasurement<?>> antennaCenteredMeasurements =
155                         EstimationTestUtils.createMeasurements(p2,
156                                                                new OneWayGNSSPhaseCreator(ephemeris,
157                                                                                           "remote", RADIO_WAVE,
158                                                                                           ambiguity,
159                                                                                           localClockOffset,
160                                                                                           remoteClockOffset,
161                                                                                           apc1, apc2),
162                                                                1.0, 3.0, 300.0);
163 
164         final Propagator p3 = EstimationTestUtils.createPropagator(context.initialOrbit,
165                                                                    propagatorBuilder);
166 
167         OnBoardAntennaOneWayGNSSPhaseModifier modifier = new OnBoardAntennaOneWayGNSSPhaseModifier(apc1, apc2, p2.getAttitudeProvider());
168         for (int i = 0; i < spacecraftCenteredMeasurements.size(); ++i) {
169             OneWayGNSSPhase sr = (OneWayGNSSPhase) spacecraftCenteredMeasurements.get(i);
170             sr.addModifier(modifier);
171             EstimatedMeasurementBase<OneWayGNSSPhase> estimated = sr.estimateWithoutDerivatives(new SpacecraftState[] { p3.propagate(sr.getDate()) });
172             OneWayGNSSPhase ar = (OneWayGNSSPhase) antennaCenteredMeasurements.get(i);
173             Assertions.assertEquals(0.0, sr.getDate().durationFrom(ar.getDate()), 2.0e-8);
174             Assertions.assertEquals(ar.getObservedValue()[0] * RADIO_WAVE.getWavelength(), estimated.getEstimatedValue()[0] * RADIO_WAVE.getWavelength(), 6.0e-5);
175             Assertions.assertEquals(1,
176                                     estimated.getAppliedEffects().entrySet().stream().
177                                     filter(e -> e.getKey().getEffectName().equals("mean phase center")).count());
178         }
179 
180     }
181 
182 }