EphemerisPropagatorBuilder.java
/* Copyright 2022 Bryan Cazabonne
* 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.
* Bryan Cazabonne 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
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.orekit.propagation.conversion;
import org.orekit.attitudes.AttitudeProvider;
import org.orekit.attitudes.FrameAlignedProvider;
import org.orekit.estimation.leastsquares.AbstractBatchLSModel;
import org.orekit.estimation.leastsquares.BatchLSModel;
import org.orekit.estimation.leastsquares.ModelObserver;
import org.orekit.estimation.measurements.ObservedMeasurement;
import org.orekit.orbits.Orbit;
import org.orekit.orbits.PositionAngleType;
import org.orekit.propagation.Propagator;
import org.orekit.propagation.SpacecraftState;
import org.orekit.propagation.SpacecraftStateInterpolator;
import org.orekit.propagation.StateCovariance;
import org.orekit.propagation.analytical.Ephemeris;
import org.orekit.time.TimeInterpolator;
import org.orekit.time.TimeStampedPair;
import org.orekit.utils.ParameterDriversList;
import java.util.ArrayList;
import java.util.List;
/**
* Builder for Ephemeris propagator.
*
* @author Bryan Cazabonne
* @author Vincent Cucchietti
* @since 11.3
*/
public class EphemerisPropagatorBuilder extends AbstractPropagatorBuilder {
/** Default position scale (not used for ephemeris based estimation). */
private static final double DEFAULT_SCALE = 10.0;
/** List of spacecraft states. */
private final List<SpacecraftState> states;
/** List of covariances. **/
private final List<StateCovariance> covariances;
/** Spacecraft state interpolator. */
private final TimeInterpolator<SpacecraftState> stateInterpolator;
/** State covariance interpolator. */
private final TimeInterpolator<TimeStampedPair<Orbit, StateCovariance>> covarianceInterpolator;
/** Attitude provider. */
private final AttitudeProvider provider;
/**
* Constructor using the default attitude provider.
* <p>
* The default attitude provider is an {@link org.orekit.attitudes.FrameAlignedProvider inertial provider} built from the frame of the first
* spacecraft state instance in given list
*
* @param states list of spacecraft states
* @param stateInterpolator spacecraft state interpolator
*/
public EphemerisPropagatorBuilder(final List<SpacecraftState> states,
final TimeInterpolator<SpacecraftState> stateInterpolator) {
this(states, stateInterpolator, states.isEmpty() ? null : new FrameAlignedProvider(states.get(0).getFrame()));
}
/**
* Constructor.
*
* @param states list of spacecraft states
* @param stateInterpolator spacecraft state interpolator
* @param attitudeProvider attitude law to use
*/
public EphemerisPropagatorBuilder(final List<SpacecraftState> states,
final TimeInterpolator<SpacecraftState> stateInterpolator,
final AttitudeProvider attitudeProvider) {
this(states, stateInterpolator, new ArrayList<>(), null, attitudeProvider);
}
/**
* Constructor.
*
* @param states list of spacecraft states
* @param interpolationPoints number of interpolation points
* @param extrapolationThreshold extrapolation threshold beyond which the propagation will fail
* @param attitudeProvider attitude law to use
*/
public EphemerisPropagatorBuilder(final List<SpacecraftState> states,
final int interpolationPoints,
final double extrapolationThreshold,
final AttitudeProvider attitudeProvider) {
this(states,
new SpacecraftStateInterpolator(interpolationPoints, extrapolationThreshold,
states.get(0).getFrame(), states.get(0).getFrame()),
attitudeProvider);
}
/**
* Constructor with covariances and default attitude provider.
* <p>
* The default attitude provider is an {@link FrameAlignedProvider inertial provider} built from the frame of the first
* spacecraft state instance in given list
*
* @param states list of spacecraft states
* @param stateInterpolator spacecraft state interpolator
* @param covariances tabulated covariances associated to tabulated states
* @param covarianceInterpolator covariance interpolator
*
* @see StateCovariance
* @see FrameAlignedProvider
*/
public EphemerisPropagatorBuilder(final List<SpacecraftState> states,
final TimeInterpolator<SpacecraftState> stateInterpolator,
final List<StateCovariance> covariances,
final TimeInterpolator<TimeStampedPair<Orbit, StateCovariance>> covarianceInterpolator) {
this(states, stateInterpolator, covariances, covarianceInterpolator,
states.isEmpty() ? null : new FrameAlignedProvider(states.get(0).getFrame()));
}
/**
* Constructor.
*
* @param states list of spacecraft states
* @param stateInterpolator spacecraft state interpolator
* @param covariances tabulated covariances associated to tabulated states
* @param covarianceInterpolator covariance interpolator
* @param attitudeProvider attitude law to use
*/
public EphemerisPropagatorBuilder(final List<SpacecraftState> states,
final TimeInterpolator<SpacecraftState> stateInterpolator,
final List<StateCovariance> covariances,
final TimeInterpolator<TimeStampedPair<Orbit, StateCovariance>> covarianceInterpolator,
final AttitudeProvider attitudeProvider) {
super(states.get(0).getOrbit(), PositionAngleType.TRUE, DEFAULT_SCALE, false, attitudeProvider);
deselectDynamicParameters();
// Check input consistency the same way Ephemeris is checking consistency
Ephemeris.checkInputConsistency(states, stateInterpolator, covariances, covarianceInterpolator);
this.states = states;
this.stateInterpolator = stateInterpolator;
this.covariances = covariances == null ? new ArrayList<>() : covariances;
this.covarianceInterpolator = covarianceInterpolator;
this.provider = attitudeProvider;
}
/** {@inheritDoc} */
@Override
public EphemerisPropagatorBuilder copy() {
return new EphemerisPropagatorBuilder(states, stateInterpolator, covariances, covarianceInterpolator, provider);
}
/** {@inheritDoc}. */
@Override
public Propagator buildPropagator(final double[] normalizedParameters) {
if (!covariances.isEmpty() && covarianceInterpolator != null) {
return new Ephemeris(states, stateInterpolator, covariances, covarianceInterpolator, provider);
}
return new Ephemeris(states, stateInterpolator, provider);
}
/** {@inheritDoc} */
@Override
public AbstractBatchLSModel buildLeastSquaresModel(final PropagatorBuilder[] builders,
final List<ObservedMeasurement<?>> measurements,
final ParameterDriversList estimatedMeasurementsParameters,
final ModelObserver observer) {
return new BatchLSModel(builders, measurements, estimatedMeasurementsParameters, observer);
}
}