1 /* Copyright 2002-2018 CS Systèmes d'Information
2 * Licensed to CS Systèmes d'Information (CS) under one or more
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
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.orekit.frames;
18
19 import org.hipparchus.Field;
20 import org.hipparchus.RealFieldElement;
21 import org.hipparchus.geometry.euclidean.threed.FieldRotation;
22 import org.hipparchus.geometry.euclidean.threed.FieldVector3D;
23 import org.hipparchus.geometry.euclidean.threed.Rotation;
24 import org.hipparchus.geometry.euclidean.threed.Vector3D;
25 import org.orekit.time.AbsoluteDate;
26 import org.orekit.time.FieldAbsoluteDate;
27 import org.orekit.utils.FieldPVCoordinates;
28 import org.orekit.utils.PVCoordinates;
29
30 /** Enumerate for different types of Local Orbital Frames.
31 * @author Luc Maisonobe
32 */
33 public enum LOFType {
34
35 /** Constant for TNW frame
36 * (X axis aligned with velocity, Z axis aligned with orbital momentum).
37 * <p>
38 * The axes of this frame are parallel to the axes of the {@link #VNC} frame:
39 * <ul>
40 * <li>X<sub>TNW</sub> = X<sub>VNC</sub></li>
41 * <li>Y<sub>TNW</sub> = -Z<sub>VNC</sub></li>
42 * <li>Z<sub>TNW</sub> = Y<sub>VNC</sub></li>
43 * </ul>
44 *
45 * @see #VNC
46 */
47 TNW {
48
49 /** {@inheritDoc} */
50 public Rotation rotationFromInertial(final PVCoordinates pv) {
51 return new Rotation(pv.getVelocity(), pv.getMomentum(),
52 Vector3D.PLUS_I, Vector3D.PLUS_K);
53 }
54
55 /** {@inheritDoc} */
56 public <T extends RealFieldElement<T>> FieldRotation<T> rotationFromInertial(final Field<T> field,
57 final FieldPVCoordinates<T> pv) {
58 return new FieldRotation<>(pv.getVelocity(), pv.getMomentum(),
59 new FieldVector3D<>(field, Vector3D.PLUS_I),
60 new FieldVector3D<>(field, Vector3D.PLUS_K));
61 }
62
63 },
64
65 /** Constant for QSW frame
66 * (X axis aligned with position, Z axis aligned with orbital momentum).
67 * <p>
68 * This frame is also known as the {@link #LVLH} frame, both constants are equivalent.
69 * </p>
70 * <p>
71 * The axes of these frames are parallel to the axes of the {@link #VVLH} frame:
72 * <ul>
73 * <li>X<sub>QSW/LVLH</sub> = -Z<sub>VVLH</sub></li>
74 * <li>Y<sub>QSW/LVLH</sub> = X<sub>VVLH</sub></li>
75 * <li>Z<sub>QSW/LVLH</sub> = -Y<sub>VVLH</sub></li>
76 * </ul>
77 *
78 * @see #LVLH
79 * @see #VVLH
80 */
81 QSW {
82
83 /** {@inheritDoc} */
84 public Rotation rotationFromInertial(final PVCoordinates pv) {
85 return new Rotation(pv.getPosition(), pv.getMomentum(),
86 Vector3D.PLUS_I, Vector3D.PLUS_K);
87 }
88
89 /** {@inheritDoc} */
90 public <T extends RealFieldElement<T>> FieldRotation<T> rotationFromInertial(final Field<T> field,
91 final FieldPVCoordinates<T> pv) {
92 return new FieldRotation<>(pv.getPosition(), pv.getMomentum(),
93 new FieldVector3D<>(field, Vector3D.PLUS_I),
94 new FieldVector3D<>(field, Vector3D.PLUS_K));
95 }
96
97 },
98
99 /** Constant for Local Vertical, Local Horizontal frame
100 * (X axis aligned with position, Z axis aligned with orbital momentum).
101 * <p>
102 * This frame is also known as the {@link #QSW} frame, both constants are equivalent.
103 * </p>
104 * <p>
105 * The axes of these frames are parallel to the axes of the {@link #VVLH} frame:
106 * <ul>
107 * <li>X<sub>LVLH/QSW</sub> = -Z<sub>VVLH</sub></li>
108 * <li>Y<sub>LVLH/QSW</sub> = X<sub>VVLH</sub></li>
109 * <li>Z<sub>LVLH/QSW</sub> = -Y<sub>VVLH</sub></li>
110 * </ul>
111 *
112 * @see #QSW
113 * @see #VVLH
114 */
115 LVLH {
116
117 /** {@inheritDoc} */
118 public Rotation rotationFromInertial(final PVCoordinates pv) {
119 return new Rotation(pv.getPosition(), pv.getMomentum(),
120 Vector3D.PLUS_I, Vector3D.PLUS_K);
121 }
122
123 /** {@inheritDoc} */
124 public <T extends RealFieldElement<T>> FieldRotation<T> rotationFromInertial(final Field<T> field,
125 final FieldPVCoordinates<T> pv) {
126 return new FieldRotation<>(pv.getPosition(), pv.getMomentum(),
127 new FieldVector3D<>(field, Vector3D.PLUS_I),
128 new FieldVector3D<>(field, Vector3D.PLUS_K));
129 }
130
131 },
132
133 /** Constant for Vehicle Velocity, Local Horizontal frame
134 * (Z axis aligned with opposite of position, Y axis aligned with opposite of orbital momentum).
135 * <p>
136 * The axes of this frame are parallel to the axes of both the {@link #QSW} and {@link #LVLH} frames:
137 * <ul>
138 * <li>X<sub>VVLH</sub> = Y<sub>QSW/LVLH</sub></li>
139 * <li>Y<sub>VVLH</sub> = -Z<sub>QSW/LVLH</sub></li>
140 * <li>Z<sub>VVLH</sub> = -X<sub>QSW/LVLH</sub></li>
141 * </ul>
142 *
143 * @see #QSW
144 * @see #LVLH
145 */
146 VVLH {
147
148 /** {@inheritDoc} */
149 public Rotation rotationFromInertial(final PVCoordinates pv) {
150 return new Rotation(pv.getPosition(), pv.getMomentum(),
151 Vector3D.MINUS_K, Vector3D.MINUS_J);
152 }
153
154 /** {@inheritDoc} */
155 public <T extends RealFieldElement<T>> FieldRotation<T> rotationFromInertial(final Field<T> field,
156 final FieldPVCoordinates<T> pv) {
157 return new FieldRotation<>(pv.getPosition(), pv.getMomentum(),
158 new FieldVector3D<>(field, Vector3D.MINUS_K),
159 new FieldVector3D<>(field, Vector3D.MINUS_J));
160 }
161
162 },
163
164 /** Constant for Velocity - Normal - Co-normal frame
165 * (X axis aligned with velocity, Y axis aligned with orbital momentum).
166 * <p>
167 * The axes of this frame are parallel to the axes of the {@link #TNW} frame:
168 * <ul>
169 * <li>X<sub>VNC</sub> = X<sub>TNW</sub></li>
170 * <li>Y<sub>VNC</sub> = Z<sub>TNW</sub></li>
171 * <li>Z<sub>VNC</sub> = -Y<sub>TNW</sub></li>
172 * </ul>
173 *
174 * @see #TNW
175 */
176 VNC {
177
178 /** {@inheritDoc} */
179 public Rotation rotationFromInertial(final PVCoordinates pv) {
180 return new Rotation(pv.getVelocity(), pv.getMomentum(),
181 Vector3D.PLUS_I, Vector3D.PLUS_J);
182 }
183
184 @Override
185 public <T extends RealFieldElement<T>> FieldRotation<T> rotationFromInertial(final Field<T> field,
186 final FieldPVCoordinates<T> pv) {
187 return new FieldRotation<>(pv.getVelocity(), pv.getMomentum(),
188 new FieldVector3D<>(field, Vector3D.PLUS_I),
189 new FieldVector3D<>(field, Vector3D.PLUS_J));
190 }
191
192 };
193
194 /** Get the transform from an inertial frame defining position-velocity and the local orbital frame.
195 * @param date current date
196 * @param pv position-velocity of the spacecraft in some inertial frame
197 * @return transform from the frame where position-velocity are defined to local orbital frame
198 */
199 public Transform transformFromInertial(final AbsoluteDate date, final PVCoordinates pv) {
200
201 // compute the translation part of the transform
202 final Transform translation = new Transform(date, pv.negate());
203
204 // compute the rotation part of the transform
205 final Rotation r = rotationFromInertial(pv);
206 final Vector3D p = pv.getPosition();
207 final Vector3D momentum = pv.getMomentum();
208 final Transform rotation =
209 new Transform(date, r, new Vector3D(1.0 / p.getNormSq(), r.applyTo(momentum)));
210
211 return new Transform(date, translation, rotation);
212
213 }
214
215 /** Get the transform from an inertial frame defining position-velocity and the local orbital frame.
216 * @param date current date
217 * @param pv position-velocity of the spacecraft in some inertial frame
218 * @param <T> type of the fiels elements
219 * @return transform from the frame where position-velocity are defined to local orbital frame
220 * @since 9.0
221 */
222 public <T extends RealFieldElement<T>> FieldTransform<T> transformFromInertial(final FieldAbsoluteDate<T> date,
223 final FieldPVCoordinates<T> pv) {
224
225 // compute the translation part of the transform
226 final FieldTransform<T> translation = new FieldTransform<>(date, pv.negate());
227
228 // compute the rotation part of the transform
229 final FieldRotation<T> r = rotationFromInertial(date.getField(), pv);
230 final FieldVector3D<T> p = pv.getPosition();
231 final FieldVector3D<T> momentum = pv.getMomentum();
232 final FieldTransform<T> rotation =
233 new FieldTransform<T>(date, r, new FieldVector3D<>(p.getNormSq().reciprocal(), r.applyTo(momentum)));
234
235 return new FieldTransform<>(date, translation, rotation);
236
237 }
238
239 /** Get the rotation from inertial frame to local orbital frame.
240 * <p>
241 * This rotation does not include any time derivatives. If first
242 * time derivatives (i.e. rotation rate) is needed as well, the full
243 * {@link #transformFromInertial(AbsoluteDate, PVCoordinates) transformFromInertial}
244 * method must be called and the complete rotation transform must be extracted
245 * from it.
246 * </p>
247 * @param pv position-velocity of the spacecraft in some inertial frame
248 * @return rotation from inertial frame to local orbital frame
249 */
250 public abstract Rotation rotationFromInertial(PVCoordinates pv);
251
252 /** Get the rotation from inertial frame to local orbital frame.
253 * <p>
254 * This rotation does not include any time derivatives. If first
255 * time derivatives (i.e. rotation rate) is needed as well, the full
256 * {@link #transformFromInertial(FieldAbsoluteDate, FieldPVCoordinates) transformFromInertial}
257 * method must be called and the complete rotation transform must be extracted
258 * from it.
259 * </p>
260 * @param field field to which the elements belong
261 * @param pv position-velocity of the spacecraft in some inertial frame
262 * @param <T> type of the field elements
263 * @return rotation from inertial frame to local orbital frame
264 * @since 9.0
265 */
266 public abstract <T extends RealFieldElement<T>> FieldRotation<T> rotationFromInertial(Field<T> field,
267 FieldPVCoordinates<T> pv);
268
269 }