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17 package org.orekit.files.general;
18
19 import org.hipparchus.geometry.euclidean.threed.Vector3D;
20 import org.orekit.attitudes.AttitudeProvider;
21 import org.orekit.errors.OrekitException;
22 import org.orekit.errors.OrekitMessages;
23 import org.orekit.files.general.EphemerisFile.EphemerisSegment;
24 import org.orekit.frames.Frame;
25 import org.orekit.orbits.CartesianOrbit;
26 import org.orekit.orbits.Orbit;
27 import org.orekit.propagation.BoundedPropagator;
28 import org.orekit.propagation.Propagator;
29 import org.orekit.propagation.SpacecraftState;
30 import org.orekit.propagation.analytical.AbstractAnalyticalPropagator;
31 import org.orekit.time.AbsoluteDate;
32 import org.orekit.utils.SortedListTrimmer;
33 import org.orekit.utils.TimeStampedPVCoordinates;
34 import org.orekit.utils.TimeStampedPVCoordinatesHermiteInterpolator;
35
36 import java.util.ArrayList;
37 import java.util.List;
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50 public class EphemerisSegmentPropagator<C extends TimeStampedPVCoordinates> extends AbstractAnalyticalPropagator
51 implements BoundedPropagator {
52
53
54 private final EphemerisSegment<C> ephemeris;
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58 private final TimeStampedPVCoordinatesHermiteInterpolator interpolator;
59
60 private final Frame inertialFrame;
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62 private final Frame ephemerisFrame;
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70 public EphemerisSegmentPropagator(final EphemerisSegment<C> ephemeris,
71 final AttitudeProvider attitudeProvider) {
72 super(attitudeProvider);
73 this.ephemeris = ephemeris;
74 this.interpolator = new TimeStampedPVCoordinatesHermiteInterpolator(ephemeris.getInterpolationSamples(),
75 ephemeris.getAvailableDerivatives());
76 this.ephemerisFrame = ephemeris.getFrame();
77 this.inertialFrame = ephemeris.getInertialFrame();
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79 final TimeStampedPVCoordinates ic = ephemeris.getCoordinates().get(0);
80 final TimeStampedPVCoordinates icInertial = ephemerisFrame
81 .getTransformTo(inertialFrame, ic.getDate())
82 .transformPVCoordinates(ic);
83 super.resetInitialState(
84 new SpacecraftState(
85 new CartesianOrbit(
86 icInertial, inertialFrame, ephemeris.getMu()
87 ),
88 getAttitudeProvider().getAttitude(
89 icInertial.toTaylorProvider(inertialFrame),
90 ic.getDate(),
91 inertialFrame)
92 ).withMass(DEFAULT_MASS)
93 );
94 }
95
96 @Override
97 public TimeStampedPVCoordinates getPVCoordinates(final AbsoluteDate date, final Frame frame) {
98 final TimeStampedPVCoordinates interpolatedPVCoordinates = interpolate(date);
99 return ephemerisFrame.getTransformTo(frame, date).transformPVCoordinates(interpolatedPVCoordinates);
100 }
101
102 @Override
103 public Vector3D getPosition(final AbsoluteDate date, final Frame frame) {
104 final Vector3D interpolatedPosition = interpolate(date).getPosition();
105 return ephemerisFrame.getStaticTransformTo(frame, date).transformPosition(interpolatedPosition);
106 }
107
108 @Override
109 public Orbit propagateOrbit(final AbsoluteDate date) {
110 final TimeStampedPVCoordinates pv = this.getPVCoordinates(date, inertialFrame);
111 return new CartesianOrbit(pv, inertialFrame, this.ephemeris.getMu());
112 }
113
114 @Override
115 public AbsoluteDate getMinDate() {
116 return ephemeris.getStart();
117 }
118
119 @Override
120 public AbsoluteDate getMaxDate() {
121 return ephemeris.getStop();
122 }
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124 @Override
125 protected double getMass(final AbsoluteDate date) {
126 return DEFAULT_MASS;
127 }
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129 @Override
130 public SpacecraftState getInitialState() {
131 return this.basicPropagate(this.getMinDate());
132 }
133
134 @Override
135 protected void resetIntermediateState(final SpacecraftState state,
136 final boolean forward) {
137 throw new OrekitException(OrekitMessages.NON_RESETABLE_STATE);
138 }
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140 @Override
141 public void resetInitialState(final SpacecraftState state) {
142 throw new OrekitException(OrekitMessages.NON_RESETABLE_STATE);
143 }
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150 private TimeStampedPVCoordinates interpolate(final AbsoluteDate date) {
151 final List<C> neighbors = new SortedListTrimmer(interpolator.getNbInterpolationPoints()).
152 getNeighborsSubList(date, ephemeris.getCoordinates());
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155 final List<TimeStampedPVCoordinates> castedNeighbors = new ArrayList<>(neighbors.size());
156 castedNeighbors.addAll(neighbors);
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159 return interpolator.interpolate(date, castedNeighbors);
160 }
161
162 }