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17 package org.orekit.files.general;
18
19 import static org.junit.Assert.assertEquals;
20 import static org.junit.Assert.assertNotNull;
21 import static org.junit.Assert.assertTrue;
22 import static org.junit.Assert.fail;
23
24 import java.io.IOException;
25 import java.nio.file.Files;
26 import java.nio.file.Paths;
27 import java.util.ArrayList;
28 import java.util.List;
29
30 import org.hipparchus.geometry.euclidean.threed.Vector3D;
31 import org.hipparchus.util.FastMath;
32 import org.junit.Before;
33 import org.junit.Test;
34 import org.orekit.Utils;
35 import org.orekit.bodies.CelestialBody;
36 import org.orekit.bodies.CelestialBodyFactory;
37 import org.orekit.bodies.GeodeticPoint;
38 import org.orekit.bodies.OneAxisEllipsoid;
39 import org.orekit.data.DataSource;
40 import org.orekit.errors.OrekitException;
41 import org.orekit.files.ccsds.definitions.BodyFacade;
42 import org.orekit.files.ccsds.definitions.FrameFacade;
43 import org.orekit.files.ccsds.definitions.TimeSystem;
44 import org.orekit.files.ccsds.ndm.ParserBuilder;
45 import org.orekit.files.ccsds.ndm.WriterBuilder;
46 import org.orekit.files.ccsds.ndm.odm.oem.EphemerisWriter;
47 import org.orekit.files.ccsds.ndm.odm.oem.OemMetadata;
48 import org.orekit.files.ccsds.ndm.odm.oem.OemParser;
49 import org.orekit.files.ccsds.ndm.odm.oem.OemSegment;
50 import org.orekit.files.ccsds.utils.FileFormat;
51 import org.orekit.files.general.EphemerisFile.EphemerisSegment;
52 import org.orekit.files.general.OrekitEphemerisFile.OrekitSatelliteEphemeris;
53 import org.orekit.frames.Frame;
54 import org.orekit.frames.FramesFactory;
55 import org.orekit.frames.TopocentricFrame;
56 import org.orekit.orbits.CartesianOrbit;
57 import org.orekit.orbits.KeplerianOrbit;
58 import org.orekit.orbits.PositionAngle;
59 import org.orekit.propagation.Propagator;
60 import org.orekit.propagation.SpacecraftState;
61 import org.orekit.propagation.analytical.Ephemeris;
62 import org.orekit.propagation.analytical.KeplerianPropagator;
63 import org.orekit.propagation.events.ElevationDetector;
64 import org.orekit.propagation.events.EventsLogger;
65 import org.orekit.propagation.events.EventsLogger.LoggedEvent;
66 import org.orekit.time.AbsoluteDate;
67 import org.orekit.utils.CartesianDerivativesFilter;
68 import org.orekit.utils.Constants;
69 import org.orekit.utils.IERSConventions;
70 import org.orekit.utils.TimeStampedPVCoordinates;
71
72 public class OrekitEphemerisFileTest {
73
74 @Before
75 public void setUp() throws Exception {
76 Utils.setDataRoot("regular-data");
77 }
78
79 @Test
80 public void testOrekitEphemerisFile() {
81 assertNotNull(new OrekitEphemerisFile());
82 }
83
84 @Test
85 public void testGetSatellites() {
86 final String id1 = "ID1";
87 final String id2 = "ID2";
88 OrekitEphemerisFile file = new OrekitEphemerisFile();
89 OrekitSatelliteEphemeris ephem1 = file.addSatellite(id1);
90 assertNotNull(ephem1);
91 OrekitSatelliteEphemeris ephem2 = file.addSatellite(id2);
92 assertNotNull(ephem2);
93 }
94
95 @Test
96 public void testWritingToOEMKvn() throws IOException {
97 doTestWritingToOEM(FileFormat.KVN);
98 }
99
100 @Test
101 public void testWritingToOEMXml() throws IOException {
102 doTestWritingToOEM(FileFormat.XML);
103 }
104
105 private void doTestWritingToOEM(final FileFormat fileFormat) throws IOException {
106 final double muTolerance = 1e-12;
107
108 final double positionTolerance = 1.;
109
110 final double velocityTolerance = 1e-2;
111 final String satId = "SATELLITE1";
112 final double sma = 10000000;
113 final double inc = Math.toRadians(45.0);
114 final double ecc = 0.001;
115 final double raan = 0.0;
116 final double pa = 0.0;
117 final double ta = 0.0;
118 final AbsoluteDate date = new AbsoluteDate();
119 final Frame frame = FramesFactory.getGCRF();
120 final CelestialBody body = CelestialBodyFactory.getEarth();
121 final double mu = body.getGM();
122 KeplerianOrbit initialOrbit = new KeplerianOrbit(sma, ecc, inc, pa, raan, ta, PositionAngle.TRUE, frame, date,
123 mu);
124 KeplerianPropagator propagator = new KeplerianPropagator(initialOrbit);
125
126 final double propagationDurationSeconds = 86400.0;
127 final double stepSizeSeconds = 60.0;
128 List<SpacecraftState> states = new ArrayList<SpacecraftState>();
129
130 for (double dt = 0.0; dt < propagationDurationSeconds; dt += stepSizeSeconds) {
131 states.add(propagator.propagate(date.shiftedBy(dt)));
132 }
133
134 OrekitEphemerisFile ephemerisFile = new OrekitEphemerisFile();
135 OrekitSatelliteEphemeris satellite = ephemerisFile.addSatellite(satId);
136 satellite.addNewSegment(states);
137 assertEquals(satId, satellite.getId());
138 assertEquals(body.getGM(), satellite.getMu(), muTolerance);
139 assertEquals(0.0, states.get(0).getDate().durationFrom(satellite.getStart()), 1.0e-15);
140 assertEquals(0.0, states.get(states.size() - 1).getDate().durationFrom(satellite.getStop()), 1.0e-15);
141 assertEquals(CartesianDerivativesFilter.USE_PV,
142 satellite.getSegments().get(0).getAvailableDerivatives());
143 assertEquals("GCRF",
144 satellite.getSegments().get(0).getFrame().getName());
145 assertEquals(body.getGM(),
146 satellite.getSegments().get(0).getMu(), muTolerance);
147
148 String tempOem = Files.createTempFile("OrekitEphemerisFileTest", ".oem").toString();
149 OemMetadata template = new OemMetadata(2);
150 template.setTimeSystem(TimeSystem.UTC);
151 template.setObjectID(satId);
152 template.setObjectName(satId);
153 template.setCenter(new BodyFacade("EARTH", CelestialBodyFactory.getCelestialBodies().getEarth()));
154 template.setReferenceFrame(FrameFacade.map(FramesFactory.getEME2000()));
155 EphemerisWriter writer = new EphemerisWriter(new WriterBuilder().buildOemWriter(),
156 null, template, fileFormat, "dummy", 60);
157 writer.write(tempOem, ephemerisFile);
158
159 OemParser parser = new ParserBuilder().withMu(body.getGM()).withDefaultInterpolationDegree(2).buildOemParser();
160 EphemerisFile<TimeStampedPVCoordinates, OemSegment> ephemerisFrom = parser.parse(new DataSource(tempOem));
161 Files.delete(Paths.get(tempOem));
162
163 EphemerisSegment<TimeStampedPVCoordinates> segment = ephemerisFrom.getSatellites().get(satId).getSegments().get(0);
164 assertEquals(states.get(0).getDate(), segment.getStart());
165 assertEquals(states.get(states.size() - 1).getDate(), segment.getStop());
166 assertEquals(states.size(), segment.getCoordinates().size());
167 assertEquals(frame, segment.getFrame());
168 assertEquals(body.getGM(), segment.getMu(), muTolerance);
169 assertEquals(CartesianDerivativesFilter.USE_PV, segment.getAvailableDerivatives());
170 assertEquals("GCRF", segment.getFrame().getName());
171 for (int i = 0; i < states.size(); i++) {
172 TimeStampedPVCoordinates expected = states.get(i).getPVCoordinates();
173 TimeStampedPVCoordinates actual = segment.getCoordinates().get(i);
174 assertEquals(expected.getDate(), actual.getDate());
175 assertEquals(0.0, Vector3D.distance(expected.getPosition(), actual.getPosition()), positionTolerance);
176 assertEquals(0.0, Vector3D.distance(expected.getVelocity(), actual.getVelocity()), velocityTolerance);
177 }
178
179
180 final OneAxisEllipsoid parentShape = new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS,
181 Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true));
182 final double latitude = 0.0;
183 final double longitude = 0.0;
184 final double altitude = 0.0;
185 final GeodeticPoint point = new GeodeticPoint(latitude, longitude, altitude);
186 final TopocentricFrame topo = new TopocentricFrame(parentShape, point, "testPoint1");
187 final ElevationDetector elevationDetector = new ElevationDetector(topo);
188 final EphemerisSegmentPropagator<TimeStampedPVCoordinates> ephemerisSegmentPropagator =
189 new EphemerisSegmentPropagator<>(segment);
190 final EventsLogger lookupLogger = new EventsLogger();
191 ephemerisSegmentPropagator.addEventDetector(lookupLogger.monitorDetector(elevationDetector));
192
193 final EventsLogger referenceLogger = new EventsLogger();
194 propagator.clearEventsDetectors();
195 propagator.addEventDetector(referenceLogger.monitorDetector(elevationDetector));
196
197 propagator.propagate(segment.getStart(), segment.getStop());
198 ephemerisSegmentPropagator.propagate(segment.getStart(), segment.getStop());
199
200 final double dateEpsilon = 4.2e-5;
201 assertTrue(referenceLogger.getLoggedEvents().size() > 0);
202 assertEquals(referenceLogger.getLoggedEvents().size(), lookupLogger.getLoggedEvents().size());
203 for (int i = 0; i < referenceLogger.getLoggedEvents().size(); i++) {
204 LoggedEvent reference = referenceLogger.getLoggedEvents().get(i);
205 LoggedEvent actual = lookupLogger.getLoggedEvents().get(i);
206 assertEquals(0.0,
207 FastMath.abs(reference.getState().getDate().durationFrom(actual.getState().getDate())),
208 dateEpsilon);
209 }
210
211 final Propagator embeddedPropagator = segment.getPropagator();
212 final EventsLogger embeddedPropLogger = new EventsLogger();
213 embeddedPropagator.addEventDetector(embeddedPropLogger.monitorDetector(elevationDetector));
214 embeddedPropagator.propagate(segment.getStart(), segment.getStop());
215 assertEquals(referenceLogger.getLoggedEvents().size(), embeddedPropLogger.getLoggedEvents().size());
216 for (int i = 0; i < referenceLogger.getLoggedEvents().size(); i++) {
217 LoggedEvent reference = referenceLogger.getLoggedEvents().get(i);
218 LoggedEvent actual = embeddedPropLogger.getLoggedEvents().get(i);
219 assertEquals(0.0,
220 FastMath.abs(reference.getState().getDate().durationFrom(actual.getState().getDate())),
221 dateEpsilon);
222
223 }
224
225 final List<SpacecraftState> readInStates = new ArrayList<SpacecraftState>();
226 segment.getCoordinates().forEach(c -> {
227 try {
228 readInStates.add(new SpacecraftState(new CartesianOrbit(c, frame, mu)));
229 } catch (IllegalArgumentException | OrekitException e) {
230 fail(e.getLocalizedMessage());
231 }
232 });
233
234 final int interpolationPoints = 5;
235 Ephemeris directEphemProp = new Ephemeris(readInStates, interpolationPoints);
236 final EventsLogger directEphemPropLogger = new EventsLogger();
237 directEphemProp.addEventDetector(directEphemPropLogger.monitorDetector(elevationDetector));
238 directEphemProp.propagate(segment.getStart(), segment.getStop());
239 assertEquals(referenceLogger.getLoggedEvents().size(), directEphemPropLogger.getLoggedEvents().size());
240 for (int i = 0; i < referenceLogger.getLoggedEvents().size(); i++) {
241 LoggedEvent reference = referenceLogger.getLoggedEvents().get(i);
242 LoggedEvent actual = directEphemPropLogger.getLoggedEvents().get(i);
243 assertEquals(0.0,
244 FastMath.abs(reference.getState().getDate().durationFrom(actual.getState().getDate())),
245 dateEpsilon);
246 }
247
248 }
249
250 }