FieldAbsolutePVCoordinates.java
/* Copyright 2002-2024 CS GROUP
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* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* CS licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
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*
* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing, software
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package org.orekit.utils;
import org.hipparchus.CalculusFieldElement;
import org.hipparchus.Field;
import org.hipparchus.analysis.differentiation.DerivativeStructure;
import org.hipparchus.analysis.differentiation.FieldDerivative;
import org.hipparchus.geometry.euclidean.threed.FieldVector3D;
import org.orekit.errors.OrekitException;
import org.orekit.errors.OrekitIllegalArgumentException;
import org.orekit.errors.OrekitMessages;
import org.orekit.frames.FieldStaticTransform;
import org.orekit.frames.FieldTransform;
import org.orekit.frames.Frame;
import org.orekit.time.FieldAbsoluteDate;
import org.orekit.time.FieldTimeStamped;
/** Field implementation of AbsolutePVCoordinates.
* @see AbsolutePVCoordinates
* @author Vincent Mouraux
* @param <T> type of the field elements
*/
public class FieldAbsolutePVCoordinates<T extends CalculusFieldElement<T>> extends TimeStampedFieldPVCoordinates<T>
implements FieldTimeStamped<T>, FieldPVCoordinatesProvider<T> {
/** Frame in which are defined the coordinates. */
private final Frame frame;
/** Build from position, velocity, acceleration.
* @param frame the frame in which the coordinates are defined
* @param date coordinates date
* @param position the position vector (m)
* @param velocity the velocity vector (m/s)
* @param acceleration the acceleration vector (m/sÂý)
*/
public FieldAbsolutePVCoordinates(final Frame frame, final FieldAbsoluteDate<T> date,
final FieldVector3D<T> position, final FieldVector3D<T> velocity, final FieldVector3D<T> acceleration) {
super(date, position, velocity, acceleration);
this.frame = frame;
}
/** Build from position and velocity. Acceleration is set to zero.
* @param frame the frame in which the coordinates are defined
* @param date coordinates date
* @param position the position vector (m)
* @param velocity the velocity vector (m/s)
*/
public FieldAbsolutePVCoordinates(final Frame frame, final FieldAbsoluteDate<T> date,
final FieldVector3D<T> position,
final FieldVector3D<T> velocity) {
this(frame, date, position, velocity, FieldVector3D.getZero(date.getField()));
}
/** Build from frame, date and FieldPVA coordinates.
* @param frame the frame in which the coordinates are defined
* @param date date of the coordinates
* @param pva TimeStampedPVCoordinates
*/
public FieldAbsolutePVCoordinates(final Frame frame, final FieldAbsoluteDate<T> date, final FieldPVCoordinates<T> pva) {
super(date, pva);
this.frame = frame;
}
/** Build from frame and TimeStampedFieldPVCoordinates.
* @param frame the frame in which the coordinates are defined
* @param pva TimeStampedFieldPVCoordinates
*/
public FieldAbsolutePVCoordinates(final Frame frame, final TimeStampedFieldPVCoordinates<T> pva) {
super(pva.getDate(), pva);
this.frame = frame;
}
/** Build from Field and non-Fielded object.
* @param field field
* @param pva non-Field AbsolutePVCoordinates
*/
public FieldAbsolutePVCoordinates(final Field<T> field, final AbsolutePVCoordinates pva) {
this(pva.getFrame(), new TimeStampedFieldPVCoordinates<>(field, pva));
}
/** Multiplicative constructor
* <p>Build a FieldAbsolutePVCoordinates from another one and a scale factor.</p>
* <p>The TimeStampedFieldPVCoordinates built will be a * AbsPva</p>
* @param date date of the built coordinates
* @param a scale factor
* @param AbsPva base (unscaled) FieldAbsolutePVCoordinates
*/
public FieldAbsolutePVCoordinates(final FieldAbsoluteDate<T> date,
final T a, final FieldAbsolutePVCoordinates<T> AbsPva) {
super(date, a, AbsPva);
this.frame = AbsPva.frame;
}
/** Subtractive constructor
* <p>Build a relative FieldAbsolutePVCoordinates from a start and an end position.</p>
* <p>The FieldAbsolutePVCoordinates built will be end - start.</p>
* <p>In case start and end use two different pseudo-inertial frames,
* the new FieldAbsolutePVCoordinates arbitrarily be defined in the start frame. </p>
* @param date date of the built coordinates
* @param start Starting FieldAbsolutePVCoordinates
* @param end ending FieldAbsolutePVCoordinates
*/
public FieldAbsolutePVCoordinates(final FieldAbsoluteDate<T> date,
final FieldAbsolutePVCoordinates<T> start, final FieldAbsolutePVCoordinates<T> end) {
super(date, start, end);
ensureIdenticalFrames(start, end);
this.frame = start.frame;
}
/** Linear constructor
* <p>Build a FieldAbsolutePVCoordinates from two other ones and corresponding scale factors.</p>
* <p>The FieldAbsolutePVCoordinates built will be a1 * u1 + a2 * u2</p>
* <p>In case the FieldAbsolutePVCoordinates use different pseudo-inertial frames,
* the new FieldAbsolutePVCoordinates arbitrarily be defined in the first frame. </p>
* @param date date of the built coordinates
* @param a1 first scale factor
* @param absPv1 first base (unscaled) FieldAbsolutePVCoordinates
* @param a2 second scale factor
* @param absPv2 second base (unscaled) FieldAbsolutePVCoordinates
*/
public FieldAbsolutePVCoordinates(final FieldAbsoluteDate<T> date,
final T a1, final FieldAbsolutePVCoordinates<T> absPv1,
final T a2, final FieldAbsolutePVCoordinates<T> absPv2) {
super(date, a1, absPv1.getPVCoordinates(), a2, absPv2.getPVCoordinates());
ensureIdenticalFrames(absPv1, absPv2);
this.frame = absPv1.getFrame();
}
/** Linear constructor
* <p>Build a FieldAbsolutePVCoordinates from three other ones and corresponding scale factors.</p>
* <p>The FieldAbsolutePVCoordinates built will be a1 * u1 + a2 * u2 + a3 * u3</p>
* <p>In case the FieldAbsolutePVCoordinates use different pseudo-inertial frames,
* the new FieldAbsolutePVCoordinates arbitrarily be defined in the first frame. </p>
* @param date date of the built coordinates
* @param a1 first scale factor
* @param absPv1 first base (unscaled) FieldAbsolutePVCoordinates
* @param a2 second scale factor
* @param absPv2 second base (unscaled) FieldAbsolutePVCoordinates
* @param a3 third scale factor
* @param absPv3 third base (unscaled) FieldAbsolutePVCoordinates
*/
public FieldAbsolutePVCoordinates(final FieldAbsoluteDate<T> date,
final T a1, final FieldAbsolutePVCoordinates<T> absPv1,
final T a2, final FieldAbsolutePVCoordinates<T> absPv2,
final T a3, final FieldAbsolutePVCoordinates<T> absPv3) {
super(date, a1, absPv1.getPVCoordinates(), a2, absPv2.getPVCoordinates(),
a3, absPv3.getPVCoordinates());
ensureIdenticalFrames(absPv1, absPv2);
ensureIdenticalFrames(absPv1, absPv3);
this.frame = absPv1.getFrame();
}
/** Linear constructor
* <p>Build a FieldAbsolutePVCoordinates from four other ones and corresponding scale factors.</p>
* <p>The FieldAbsolutePVCoordinates built will be a1 * u1 + a2 * u2 + a3 * u3 + a4 * u4</p>
* <p>In case the FieldAbsolutePVCoordinates use different pseudo-inertial frames,
* the new AbsolutePVCoordinates arbitrarily be defined in the first frame. </p>
* @param date date of the built coordinates
* @param a1 first scale factor
* @param absPv1 first base (unscaled) FieldAbsolutePVCoordinates
* @param a2 second scale factor
* @param absPv2 second base (unscaled) FieldAbsolutePVCoordinates
* @param a3 third scale factor
* @param absPv3 third base (unscaled) FieldAbsolutePVCoordinates
* @param a4 fourth scale factor
* @param absPv4 fourth base (unscaled) FieldAbsolutePVCoordinates
*/
public FieldAbsolutePVCoordinates(final FieldAbsoluteDate<T> date,
final T a1, final FieldAbsolutePVCoordinates<T> absPv1,
final T a2, final FieldAbsolutePVCoordinates<T> absPv2,
final T a3, final FieldAbsolutePVCoordinates<T> absPv3,
final T a4, final FieldAbsolutePVCoordinates<T> absPv4) {
super(date, a1, absPv1.getPVCoordinates(), a2, absPv2.getPVCoordinates(),
a3, absPv3.getPVCoordinates(), a4, absPv4.getPVCoordinates());
ensureIdenticalFrames(absPv1, absPv2);
ensureIdenticalFrames(absPv1, absPv3);
ensureIdenticalFrames(absPv1, absPv4);
this.frame = absPv1.getFrame();
}
/** Builds a FieldAbsolutePVCoordinates triplet from a {@link FieldVector3D}<{@link DerivativeStructure}>.
* <p>
* The vector components must have time as their only derivation parameter and
* have consistent derivation orders.
* </p>
* @param frame the frame in which the parameters are defined
* @param date date of the built coordinates
* @param p vector with time-derivatives embedded within the coordinates
* @param <U> type of the derivative
*/
public <U extends FieldDerivative<T, U>> FieldAbsolutePVCoordinates(final Frame frame, final FieldAbsoluteDate<T> date,
final FieldVector3D<U> p) {
super(date, p);
this.frame = frame;
}
/** Ensure that the frames from two FieldAbsolutePVCoordinates are identical.
* @param absPv1 first FieldAbsolutePVCoordinates
* @param absPv2 first FieldAbsolutePVCoordinates
* @param <T> the type of the field elements
* @throws OrekitIllegalArgumentException if frames are different
*/
private static <T extends CalculusFieldElement<T>> void ensureIdenticalFrames(final FieldAbsolutePVCoordinates<T> absPv1, final FieldAbsolutePVCoordinates<T> absPv2)
throws OrekitIllegalArgumentException {
if (!absPv1.frame.equals(absPv2.frame)) {
throw new OrekitIllegalArgumentException(OrekitMessages.INCOMPATIBLE_FRAMES,
absPv1.frame.getName(), absPv2.frame.getName());
}
}
/** Get a time-shifted state.
* <p>
* The state can be slightly shifted to close dates. This shift is based on
* a simple Taylor expansion. It is <em>not</em> intended as a replacement for
* proper orbit propagation (it is not even Keplerian!) but should be sufficient
* for either small time shifts or coarse accuracy.
* </p>
* @param dt time shift in seconds
* @return a new state, shifted with respect to the instance (which is immutable)
*/
public FieldAbsolutePVCoordinates<T> shiftedBy(final T dt) {
final TimeStampedFieldPVCoordinates<T> spv = super.shiftedBy(dt);
return new FieldAbsolutePVCoordinates<>(frame, spv);
}
/** Get a time-shifted state.
* <p>
* The state can be slightly shifted to close dates. This shift is based on
* a simple Taylor expansion. It is <em>not</em> intended as a replacement for
* proper orbit propagation (it is not even Keplerian!) but should be sufficient
* for either small time shifts or coarse accuracy.
* </p>
* @param dt time shift in seconds
* @return a new state, shifted with respect to the instance (which is immutable)
*/
public FieldAbsolutePVCoordinates<T> shiftedBy(final double dt) {
final TimeStampedFieldPVCoordinates<T> spv = super.shiftedBy(dt);
return new FieldAbsolutePVCoordinates<>(frame, spv);
}
/** Create a local provider using simply Taylor expansion through {@link #shiftedBy(double)}.
* <p>
* The time evolution is based on a simple Taylor expansion. It is <em>not</em> intended as a
* replacement for proper orbit propagation (it is not even Keplerian!) but should be sufficient
* for either small time shifts or coarse accuracy.
* </p>
* @return provider based on Taylor expansion, for small time shifts around instance date
*/
public FieldPVCoordinatesProvider<T> toTaylorProvider() {
return new FieldPVCoordinatesProvider<T>() {
/** {@inheritDoc} */
public FieldVector3D<T> getPosition(final FieldAbsoluteDate<T> d, final Frame f) {
final TimeStampedFieldPVCoordinates<T> shifted = shiftedBy(d.durationFrom(getDate()));
final FieldStaticTransform<T> transform = frame.getStaticTransformTo(f, d);
return transform.transformPosition(shifted.getPosition());
}
/** {@inheritDoc} */
public TimeStampedFieldPVCoordinates<T> getPVCoordinates(final FieldAbsoluteDate<T> d, final Frame f) {
final TimeStampedFieldPVCoordinates<T> shifted = shiftedBy(d.durationFrom(getDate()));
final FieldTransform<T> transform = frame.getTransformTo(f, d);
return transform.transformPVCoordinates(shifted);
}
};
}
/** Get the frame in which the coordinates are defined.
* @return frame in which the coordinates are defined
*/
public Frame getFrame() {
return frame;
}
/** Get the TimeStampedFieldPVCoordinates.
* @return TimeStampedFieldPVCoordinates
*/
public TimeStampedFieldPVCoordinates<T> getPVCoordinates() {
return this;
}
/** Get the position in a specified frame.
* @param outputFrame frame in which the position coordinates shall be computed
* @return position
* @see #getPVCoordinates(Frame)
* @since 12.0
*/
public FieldVector3D<T> getPosition(final Frame outputFrame) {
// If output frame requested is the same as definition frame,
// Position vector is returned directly
if (outputFrame == frame) {
return getPosition();
}
// Else, position vector is transformed to output frame
final FieldStaticTransform<T> t = frame.getStaticTransformTo(outputFrame, getDate());
return t.transformPosition(getPosition());
}
/** Get the TimeStampedFieldPVCoordinates in a specified frame.
* @param outputFrame frame in which the position/velocity coordinates shall be computed
* @return TimeStampedFieldPVCoordinates
* @exception OrekitException if transformation between frames cannot be computed
* @see #getPVCoordinates()
*/
public TimeStampedFieldPVCoordinates<T> getPVCoordinates(final Frame outputFrame) {
// If output frame requested is the same as definition frame,
// PV coordinates are returned directly
if (outputFrame == frame) {
return getPVCoordinates();
}
// Else, PV coordinates are transformed to output frame
final FieldTransform<T> t = frame.getTransformTo(outputFrame, getDate());
return t.transformPVCoordinates(getPVCoordinates());
}
@Override
public TimeStampedFieldPVCoordinates<T> getPVCoordinates(final FieldAbsoluteDate<T> otherDate, final Frame outputFrame) {
return shiftedBy(otherDate.durationFrom(getDate())).getPVCoordinates(outputFrame);
}
/**
* Converts to an AbsolutePVCoordinates instance.
* @return AbsolutePVCoordinates with same properties
*/
public AbsolutePVCoordinates toAbsolutePVCoordinates() {
return new AbsolutePVCoordinates(frame, this.getDate()
.toAbsoluteDate(), this.getPVCoordinates().toPVCoordinates());
}
}