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17 package org.orekit.bodies;
18
19 import org.hipparchus.geometry.euclidean.threed.Rotation;
20 import org.hipparchus.geometry.euclidean.threed.Vector3D;
21 import org.hipparchus.util.FastMath;
22 import org.junit.Assert;
23 import org.junit.Before;
24 import org.junit.Test;
25 import org.orekit.Utils;
26 import org.orekit.frames.Frame;
27 import org.orekit.frames.Transform;
28 import org.orekit.time.AbsoluteDate;
29 import org.orekit.time.TimeScale;
30 import org.orekit.time.TimeScalesFactory;
31 import org.orekit.utils.AbsolutePVCoordinates;
32 import org.orekit.utils.LagrangianPoints;
33 import org.orekit.utils.PVCoordinates;
34
35 public class CR3BPSystemTest {
36
37 @Before
38 public void setUp() {
39 Utils.setDataRoot("cr3bp:regular-data");
40 }
41
42 @Test
43 public void testCR3BPSystem() {
44 AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
45 TimeScale timeScale = TimeScalesFactory.getUTC();
46 final CR3BPSystem syst = CR3BPFactory.getSunEarthCR3BP(date, timeScale);
47 final double lDim = syst.getDdim();
48 Assert.assertNotNull(lDim);
49
50 final double vDim = syst.getVdim();
51 Assert.assertNotNull(vDim);
52
53 final double tDim = syst.getTdim();
54 Assert.assertNotNull(tDim);
55 }
56
57 @Test
58 public void testGetRotatingFrame() {
59 AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
60 TimeScale timeScale = TimeScalesFactory.getUTC();
61 final Frame baryFrame = CR3BPFactory.getSunEarthCR3BP(date, timeScale).getRotatingFrame();
62 Assert.assertNotNull(baryFrame);
63 }
64
65 @Test
66 public void testGetPrimary() {
67 AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
68 TimeScale timeScale = TimeScalesFactory.getUTC();
69 final CelestialBody primaryBody = CR3BPFactory.getSunEarthCR3BP(date, timeScale).getPrimary();
70 Assert.assertNotNull(primaryBody);
71 }
72
73 @Test
74 public void testGetSecondary() {
75 AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
76 TimeScale timeScale = TimeScalesFactory.getUTC();
77 final CelestialBody secondaryBody = CR3BPFactory.getSunEarthCR3BP(date, timeScale).getSecondary();
78 Assert.assertNotNull(secondaryBody);
79 }
80
81 @Test
82 public void testGetMu() {
83 AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
84 TimeScale timeScale = TimeScalesFactory.getUTC();
85 final double mu = CR3BPFactory.getSunJupiterCR3BP(date, timeScale).getMassRatio();
86 Assert.assertNotNull(mu);
87 }
88
89 @Test
90 public void testGetName() {
91 AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
92 TimeScale timeScale = TimeScalesFactory.getUTC();
93 final String name = CR3BPFactory.getSunEarthCR3BP(date, timeScale).getName();
94 Assert.assertNotNull(name);
95 }
96
97 @Test
98 public void testGetLPos() {
99 final CR3BPSystem syst = CR3BPFactory.getEarthMoonCR3BP();
100
101 final Vector3D l1Position = syst.getLPosition(LagrangianPoints.L1);
102 Assert.assertEquals(3.23E8, l1Position.getX() * syst.getDdim(),3E6);
103 Assert.assertEquals(0.0, l1Position.getY() * syst.getDdim(),1E3);
104 Assert.assertEquals(0.0, l1Position.getZ() * syst.getDdim(),1E3);
105
106 final Vector3D l2Position = syst.getLPosition(LagrangianPoints.L2);
107 Assert.assertEquals(4.45E8, l2Position.getX() * syst.getDdim(),3E6);
108 Assert.assertEquals(0.0, l2Position.getY() * syst.getDdim(),1E3);
109 Assert.assertEquals(0.0, l2Position.getZ() * syst.getDdim(),1E3);
110
111 final Vector3D l3Position = syst.getLPosition(LagrangianPoints.L3);
112 Assert.assertEquals(-3.86E8, l3Position.getX() * syst.getDdim(),3E6);
113 Assert.assertEquals(0.0, l3Position.getY() * syst.getDdim(),1E3);
114 Assert.assertEquals(0.0, l3Position.getZ() * syst.getDdim(),1E3);
115
116 final Vector3D l4Position = syst.getLPosition(LagrangianPoints.L4);
117 Assert.assertEquals(1.87E8, l4Position.getX() * syst.getDdim(),3E6);
118 Assert.assertEquals(3.32E8, l4Position.getY() * syst.getDdim(),3E6);
119 Assert.assertEquals(0.0, l4Position.getZ() * syst.getDdim(),1E3);
120
121 final Vector3D l5Position = syst.getLPosition(LagrangianPoints.L5);
122 Assert.assertEquals(1.87E8, l5Position.getX() * syst.getDdim(),3E6);
123 Assert.assertEquals(-3.32E8, l5Position.getY() * syst.getDdim(),3E6);
124 Assert.assertEquals(0.0, l5Position.getZ() * syst.getDdim(),1E3);
125 }
126
127 @Test
128 public void testGetGamma() {
129 TimeScale timeScale = TimeScalesFactory.getUTC();
130 AbsoluteDate date = new AbsoluteDate(2020, 7, 5, 12, 0, 0.0, timeScale);
131 final CR3BPSystem syst = CR3BPFactory.getSunEarthCR3BP(date, timeScale);
132
133 final double l1Gamma = syst.getGamma(LagrangianPoints.L1);
134 Assert.assertEquals(1.497655E9, l1Gamma * syst.getDdim(),1E3);
135
136
137 final double l2Gamma = syst.getGamma(LagrangianPoints.L2);
138 Assert.assertEquals(1.507691E9, l2Gamma * syst.getDdim(),1E3);
139
140
141 final double l3Gamma = syst.getGamma(LagrangianPoints.L3);
142 Assert.assertEquals(1.495981555E11, l3Gamma * syst.getDdim(),9E3);
143 }
144
145 @Test
146 public void testGetRealAPV() {
147
148
149 final TimeScale timeScale = TimeScalesFactory.getUTC();
150 final AbsoluteDate initialDate =
151 new AbsoluteDate(1996, 06, 26, 0, 0, 00.000,
152 TimeScalesFactory.getUTC());
153
154 final CR3BPSystem syst = CR3BPFactory.getSunEarthCR3BP(initialDate, timeScale);
155
156 final CelestialBody primaryBody = syst.getPrimary();
157 final CelestialBody secondaryBody = syst.getSecondary();
158
159 final PVCoordinates pv0 = new PVCoordinates(new Vector3D(0,0,1), new Vector3D(0,0,0));
160
161 final Frame outputFrame = secondaryBody.getInertiallyOrientedFrame();
162
163
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165
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167
168
169 final Frame primaryInertialFrame = primaryBody.getInertiallyOrientedFrame();
170 final PVCoordinates pv21 = secondaryBody.getPVCoordinates(initialDate, primaryInertialFrame);
171
172
173 final double dist12 = pv21.getPosition().getNorm();
174 final double vCircular = FastMath.sqrt(secondaryBody.getGM() / dist12);
175
176
177 final PVCoordinates pvDim = new PVCoordinates((pv0.getPosition().add(new Vector3D(syst.getMassRatio(), 0, 0))).scalarMultiply(dist12),
178 pv0.getVelocity().scalarMultiply(vCircular));
179
180
181 final double[][] c = (new Rotation(Vector3D.PLUS_I, Vector3D.PLUS_K,
182 pv21.getPosition(), pv21.getMomentum())).getMatrix();
183
184
185 final double theta = pv21.getMomentum().getNorm() / (dist12 * dist12);
186
187 final double x = pvDim.getPosition().getX();
188 final double y = pvDim.getPosition().getY();
189 final double z = pvDim.getPosition().getZ();
190 final double vx = pvDim.getVelocity().getX();
191 final double vy = pvDim.getVelocity().getY();
192 final double vz = pvDim.getVelocity().getZ();
193
194
195 final Vector3D newPos = new Vector3D(c[0][0] * x + c[0][1] * y + c[0][2] * z,
196 c[1][0] * x + c[1][1] * y + c[1][2] * z,
197 c[2][0] * x + c[2][1] * y + c[2][2] * z);
198
199 final Vector3D vel0 = new Vector3D(c[0][0] * vx + c[0][1] * vy + c[0][2] * vz,
200 c[1][0] * vx + c[1][1] * vy + c[1][2] * vz,
201 c[2][0] * vx + c[2][1] * vy + c[2][2] * vz);
202 final Vector3D addVel = new Vector3D(c[0][1] * x - c[0][0] * y,
203 c[1][1] * x - c[1][0] * y,
204 c[2][1] * x - c[2][0] * y);
205 final Vector3D newVel = vel0.add(addVel.scalarMultiply(theta));
206
207
208 final PVCoordinates pv2 = new PVCoordinates(newPos, newVel);
209
210
211 final Transform primaryInertialToOutputFrame = primaryInertialFrame.getTransformTo(outputFrame, initialDate);
212
213 final PVCoordinates pvMat = primaryInertialToOutputFrame.transformPVCoordinates(pv2);
214 final AbsolutePVCoordinates apv0 = new AbsolutePVCoordinates(outputFrame,initialDate,pv0);
215 final AbsolutePVCoordinates apvTrans = syst.getRealAPV(apv0,initialDate,outputFrame);
216
217 Assert.assertEquals(pvMat.getPosition().getX(),apvTrans.getPosition().getX(),1E-5);
218 Assert.assertEquals(pvMat.getPosition().getY(),apvTrans.getPosition().getY(),1E-15);
219 Assert.assertEquals(pvMat.getPosition().getZ(),apvTrans.getPosition().getZ(),1E-4);
220
221 Assert.assertEquals(pvMat.getVelocity().getX(),apvTrans.getVelocity().getX(),1E-2);
222 Assert.assertEquals(pvMat.getVelocity().getY(),apvTrans.getVelocity().getY(),4E-2);
223 Assert.assertEquals(pvMat.getVelocity().getZ(),apvTrans.getVelocity().getZ(),2E-2);
224
225 Assert.assertEquals(initialDate.durationFrom(AbsoluteDate.J2000_EPOCH),
226 apvTrans.getDate().durationFrom(AbsoluteDate.J2000_EPOCH),
227 1E-10);
228 }
229 }