AbsolutePVCoordinates.java
/* Copyright 2002-2025 CS GROUP
* Licensed to CS GROUP (CS) under one or more
* 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
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
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package org.orekit.utils;
import org.hipparchus.analysis.differentiation.Derivative;
import org.hipparchus.geometry.euclidean.threed.FieldVector3D;
import org.hipparchus.geometry.euclidean.threed.Vector3D;
import org.orekit.annotation.DefaultDataContext;
import org.orekit.errors.OrekitIllegalArgumentException;
import org.orekit.errors.OrekitMessages;
import org.orekit.frames.Frame;
import org.orekit.time.AbsoluteDate;
import org.orekit.time.TimeOffset;
/** Position - Velocity - Acceleration linked to a date and a frame.
*/
public class AbsolutePVCoordinates implements ShiftablePVCoordinatesHolder<AbsolutePVCoordinates>, PVCoordinatesProvider {
/** Frame in which are defined the coordinates. */
private final Frame frame;
/** Position-velocity-acceleration vector. */
private final TimeStampedPVCoordinates timeStampedPVCoordinates;
/** 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 AbsolutePVCoordinates(final Frame frame, final AbsoluteDate date,
final Vector3D position, final Vector3D velocity, final Vector3D acceleration) {
this.timeStampedPVCoordinates = new TimeStampedPVCoordinates(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 AbsolutePVCoordinates(final Frame frame, final AbsoluteDate date,
final Vector3D position,
final Vector3D velocity) {
this(frame, date, position, velocity, Vector3D.ZERO);
}
/** Build from frame, date and PVA coordinates.
* @param frame the frame in which the coordinates are defined
* @param date date of the coordinates
* @param pva TimeStampedPVCoordinates
*/
public AbsolutePVCoordinates(final Frame frame, final AbsoluteDate date, final PVCoordinates pva) {
this(frame, new TimeStampedPVCoordinates(date, pva));
}
/** Build from frame and TimeStampedPVCoordinates.
* @param frame the frame in which the coordinates are defined
* @param pva TimeStampedPVCoordinates
*/
public AbsolutePVCoordinates(final Frame frame, final TimeStampedPVCoordinates pva) {
this.timeStampedPVCoordinates = pva;
this.frame = frame;
}
/** Multiplicative constructor
* <p>Build a AbsolutePVCoordinates from another one and a scale factor.</p>
* <p>The TimeStampedPVCoordinates built will be a * AbsPva</p>
* @param date date of the built coordinates
* @param a scale factor
* @param absPva base (unscaled) AbsolutePVCoordinates
*/
public AbsolutePVCoordinates(final AbsoluteDate date,
final double a, final AbsolutePVCoordinates absPva) {
this(absPva.getFrame(), new TimeStampedPVCoordinates(date, a, absPva.getPVCoordinates()));
}
/** Subtractive constructor
* <p>Build a relative AbsolutePVCoordinates from a start and an end position.</p>
* <p>The AbsolutePVCoordinates built will be end - start.</p>
* <p>In case start and end use two different pseudo-inertial frames,
* the new AbsolutePVCoordinates arbitrarily be defined in the start frame. </p>
* @param date date of the built coordinates
* @param start Starting AbsolutePVCoordinates
* @param end ending AbsolutePVCoordinates
*/
public AbsolutePVCoordinates(final AbsoluteDate date,
final AbsolutePVCoordinates start, final AbsolutePVCoordinates end) {
this(start.getFrame(), new TimeStampedPVCoordinates(date, start.getPVCoordinates(), end.getPVCoordinates()));
ensureIdenticalFrames(start, end);
}
/** Linear constructor
* <p>Build a AbsolutePVCoordinates from two other ones and corresponding scale factors.</p>
* <p>The AbsolutePVCoordinates built will be a1 * u1 + a2 * u2</p>
* <p>In case the AbsolutePVCoordinates 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) AbsolutePVCoordinates
* @param a2 second scale factor
* @param absPv2 second base (unscaled) AbsolutePVCoordinates
*/
public AbsolutePVCoordinates(final AbsoluteDate date,
final double a1, final AbsolutePVCoordinates absPv1,
final double a2, final AbsolutePVCoordinates absPv2) {
this(absPv1.getFrame(), new TimeStampedPVCoordinates(date, a1, absPv1.getPVCoordinates(), a2, absPv2.getPVCoordinates()));
ensureIdenticalFrames(absPv1, absPv2);
}
/** Linear constructor
* <p>Build a AbsolutePVCoordinates from three other ones and corresponding scale factors.</p>
* <p>The AbsolutePVCoordinates built will be a1 * u1 + a2 * u2 + a3 * u3</p>
* <p>In case the AbsolutePVCoordinates 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) AbsolutePVCoordinates
* @param a2 second scale factor
* @param absPv2 second base (unscaled) AbsolutePVCoordinates
* @param a3 third scale factor
* @param absPv3 third base (unscaled) AbsolutePVCoordinates
*/
public AbsolutePVCoordinates(final AbsoluteDate date,
final double a1, final AbsolutePVCoordinates absPv1,
final double a2, final AbsolutePVCoordinates absPv2,
final double a3, final AbsolutePVCoordinates absPv3) {
this(absPv1.getFrame(), new TimeStampedPVCoordinates(date, a1, absPv1.getPVCoordinates(), a2,
absPv2.getPVCoordinates(), a3, absPv3.getPVCoordinates()));
ensureIdenticalFrames(absPv1, absPv2);
ensureIdenticalFrames(absPv1, absPv3);
}
/** Linear constructor
* <p>Build a AbsolutePVCoordinates from four other ones and corresponding scale factors.</p>
* <p>The AbsolutePVCoordinates built will be a1 * u1 + a2 * u2 + a3 * u3 + a4 * u4</p>
* <p>In case the AbsolutePVCoordinates 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) AbsolutePVCoordinates
* @param a2 second scale factor
* @param absPv2 second base (unscaled) AbsolutePVCoordinates
* @param a3 third scale factor
* @param absPv3 third base (unscaled) AbsolutePVCoordinates
* @param a4 fourth scale factor
* @param absPv4 fourth base (unscaled) AbsolutePVCoordinates
*/
public AbsolutePVCoordinates(final AbsoluteDate date,
final double a1, final AbsolutePVCoordinates absPv1,
final double a2, final AbsolutePVCoordinates absPv2,
final double a3, final AbsolutePVCoordinates absPv3,
final double a4, final AbsolutePVCoordinates absPv4) {
this(absPv1.getFrame(), new TimeStampedPVCoordinates(date, a1, absPv1.getPVCoordinates(), a2,
absPv2.getPVCoordinates(), a3, absPv3.getPVCoordinates(), a4, absPv4.getPVCoordinates()));
ensureIdenticalFrames(absPv1, absPv2);
ensureIdenticalFrames(absPv1, absPv3);
ensureIdenticalFrames(absPv1, absPv4);
}
/** Builds a AbsolutePVCoordinates triplet from a {@link FieldVector3D}<{@link Derivative}>.
* <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 Derivative<U>> AbsolutePVCoordinates(final Frame frame, final AbsoluteDate date,
final FieldVector3D<U> p) {
this(frame, new TimeStampedPVCoordinates(date, p));
}
/** Ensure that the frames from two AbsolutePVCoordinates are identical.
* @param absPv1 first AbsolutePVCoordinates
* @param absPv2 first AbsolutePVCoordinates
* @throws OrekitIllegalArgumentException if frames are different
*/
private static void ensureIdenticalFrames(final AbsolutePVCoordinates absPv1, final AbsolutePVCoordinates 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 AbsolutePVCoordinates shiftedBy(final double dt) {
final TimeStampedPVCoordinates spv = timeStampedPVCoordinates.shiftedBy(dt);
return new AbsolutePVCoordinates(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)
* @since 13.0
*/
@Override
public AbsolutePVCoordinates shiftedBy(final TimeOffset dt) {
final TimeStampedPVCoordinates spv = timeStampedPVCoordinates.shiftedBy(dt);
return new AbsolutePVCoordinates(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 PVCoordinatesProvider toTaylorProvider() {
return this;
}
/** Get the frame in which the coordinates are defined.
* @return frame in which the coordinates are defined
*/
public Frame getFrame() {
return frame;
}
/** {@inheritDoc} */
@Override
public AbsoluteDate getDate() {
return getPVCoordinates().getDate();
}
/** Get the TimeStampedPVCoordinates.
* @return TimeStampedPVCoordinates
*/
public TimeStampedPVCoordinates getPVCoordinates() {
return timeStampedPVCoordinates;
}
/**
* Getter for the acceleration vector.
* @return acceleration
*/
public Vector3D getAcceleration() {
return timeStampedPVCoordinates.getAcceleration();
}
/** {@inheritDoc} */
@Override
public Vector3D getPosition(final AbsoluteDate otherDate, final Frame outputFrame) {
final double duration = otherDate.durationFrom(getDate());
final Vector3D position = getPosition().add((getVelocity().add(getAcceleration().scalarMultiply(duration / 2))).scalarMultiply(duration));
if (outputFrame == frame) {
return position;
}
return frame.getStaticTransformTo(outputFrame, otherDate).transformPosition(position);
}
/** {@inheritDoc} */
@Override
@DefaultDataContext
public String toString() {
return timeStampedPVCoordinates.toString();
}
}