ShapiroPhaseModifier.java
/* Copyright 2002-2022 CS GROUP
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* this work for additional information regarding copyright ownership.
* CS licenses this file to You under the Apache License, Version 2.0
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* 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.estimation.measurements.modifiers;
import java.util.Collections;
import java.util.List;
import org.orekit.estimation.measurements.EstimatedMeasurement;
import org.orekit.estimation.measurements.EstimationModifier;
import org.orekit.estimation.measurements.gnss.Phase;
import org.orekit.utils.ParameterDriver;
import org.orekit.utils.TimeStampedPVCoordinates;
/** Class modifying theoretical phase measurement with Shapiro time delay.
* <p>
* Shapiro time delay is a relativistic effect due to gravity.
* </p>
*
* @author Bryan Cazabonne
* @author Luc Maisonobe
* @since 10.2
*/
public class ShapiroPhaseModifier extends AbstractShapiroBaseModifier implements EstimationModifier<Phase> {
/** Simple constructor.
* @param gm gravitational constant for main body in signal path vicinity.
*/
public ShapiroPhaseModifier(final double gm) {
super(gm);
}
/** {@inheritDoc} */
@Override
public List<ParameterDriver> getParametersDrivers() {
return Collections.emptyList();
}
/** {@inheritDoc} */
@Override
public void modify(final EstimatedMeasurement<Phase> estimated) {
// wavelength
final double wavelength = estimated.getObservedMeasurement().getWavelength();
// compute correction
final TimeStampedPVCoordinates[] pv = estimated.getParticipants();
final double correction = shapiroCorrection(pv[0], pv[1]) / wavelength;
// update estimated value taking into account the Shapiro time delay.
final double[] newValue = estimated.getEstimatedValue().clone();
newValue[0] = newValue[0] + correction;
estimated.setEstimatedValue(newValue);
}
}