PVBuilder.java
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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
*
* Unless required by applicable law or agreed to in writing, software
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package org.orekit.estimation.measurements.generation;
import java.util.Map;
import org.hipparchus.geometry.euclidean.threed.Vector3D;
import org.hipparchus.random.CorrelatedRandomVectorGenerator;
import org.orekit.estimation.measurements.EstimationModifier;
import org.orekit.estimation.measurements.ObservableSatellite;
import org.orekit.estimation.measurements.PV;
import org.orekit.propagation.SpacecraftState;
import org.orekit.propagation.sampling.OrekitStepInterpolator;
import org.orekit.time.AbsoluteDate;
import org.orekit.utils.ParameterDriver;
/** Builder for {@link PV} measurements.
* @author Luc Maisonobe
* @since 9.3
*/
public class PVBuilder extends AbstractMeasurementBuilder<PV> {
/** Satellite related to this builder.
* @since 12.0
*/
private final ObservableSatellite satellite;
/** Simple constructor.
* @param noiseSource noise source, may be null for generating perfect measurements
* @param sigmaPosition theoretical standard deviation on position components
* @param sigmaVelocity theoretical standard deviation on velocity components
* @param baseWeight base weight
* @param satellite satellite related to this builder
*/
public PVBuilder(final CorrelatedRandomVectorGenerator noiseSource,
final double sigmaPosition, final double sigmaVelocity,
final double baseWeight, final ObservableSatellite satellite) {
super(noiseSource,
new double[] {
sigmaPosition, sigmaVelocity
}, new double[] {
baseWeight
}, satellite);
this.satellite = satellite;
}
/** {@inheritDoc} */
@Override
public PV build(final AbsoluteDate date, final Map<ObservableSatellite, OrekitStepInterpolator> interpolators) {
final double[] sigma = getTheoreticalStandardDeviation();
final double baseWeight = getBaseWeight()[0];
final SpacecraftState[] relevant = new SpacecraftState[] { interpolators.get(satellite).getInterpolatedState(date) };
// create a dummy measurement
final PV dummy = new PV(relevant[0].getDate(), Vector3D.NaN, Vector3D.NaN,
sigma[0], sigma[1], baseWeight, satellite);
for (final EstimationModifier<PV> modifier : getModifiers()) {
dummy.addModifier(modifier);
}
// set a reference date for parameters missing one
for (final ParameterDriver driver : dummy.getParametersDrivers()) {
if (driver.getReferenceDate() == null) {
final AbsoluteDate start = getStart();
final AbsoluteDate end = getEnd();
driver.setReferenceDate(start.durationFrom(end) <= 0 ? start : end);
}
}
// estimate the perfect value of the measurement
final double[] pv = dummy.estimateWithoutDerivatives(relevant).getEstimatedValue();
// add the noise
final double[] noise = getNoise();
if (noise != null) {
pv[0] += noise[0];
pv[1] += noise[1];
pv[2] += noise[2];
pv[3] += noise[3];
pv[4] += noise[4];
pv[5] += noise[5];
}
// generate measurement
final PV measurement = new PV(relevant[0].getDate(),
new Vector3D(pv[0], pv[1], pv[2]), new Vector3D(pv[3], pv[4], pv[5]),
sigma[0], sigma[1], baseWeight, satellite);
for (final EstimationModifier<PV> modifier : getModifiers()) {
measurement.addModifier(modifier);
}
return measurement;
}
}