MeasurementHandler.java
/* Copyright 2002-2024 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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*
* 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.leastsquares;
import java.util.List;
import org.orekit.estimation.measurements.EstimatedMeasurement;
import org.orekit.estimation.measurements.ObservableSatellite;
import org.orekit.estimation.measurements.ObservedMeasurement;
import org.orekit.propagation.SpacecraftState;
import org.orekit.propagation.sampling.MultiSatStepHandler;
import org.orekit.propagation.sampling.OrekitStepInterpolator;
import org.orekit.time.AbsoluteDate;
/** {@link org.orekit.propagation.sampling.OrekitStepHandler Step handler} picking up
* {@link ObservedMeasurement measurements}.
* @author Luc Maisonobe
* @since 8.0
*/
class MeasurementHandler implements MultiSatStepHandler {
/** Least squares model. */
private final AbstractBatchLSModel model;
/** Underlying measurements. */
private final List<PreCompensation> precompensated;
/** Number of the next measurement. */
private int number;
/** Index of the next measurement component in the model. */
private int index;
/** Simple constructor.
* @param model least squares model
* @param precompensated underlying measurements
*/
MeasurementHandler(final AbstractBatchLSModel model, final List<PreCompensation> precompensated) {
this.model = model;
this.precompensated = precompensated;
}
/** {@inheritDoc} */
@Override
public void init(final List<SpacecraftState> initialStates, final AbsoluteDate target) {
number = 0;
index = 0;
}
/** {@inheritDoc} */
@Override
public void handleStep(final List<OrekitStepInterpolator> interpolators) {
while (number < precompensated.size()) {
// Consider the next measurement to handle
final PreCompensation next = precompensated.get(number);
// Current state date for interpolator 0
final AbsoluteDate currentDate = interpolators.get(0).getCurrentState().getDate();
if (model.isForwardPropagation() && next.getDate().compareTo(currentDate) > 0 ||
!model.isForwardPropagation() && next.getDate().compareTo(currentDate) < 0) {
return;
}
// get the observed measurement
final ObservedMeasurement<?> observed = next.getMeasurement();
// estimate the theoretical measurement
final SpacecraftState[] states = new SpacecraftState[observed.getSatellites().size()];
for (int i = 0; i < states.length; ++i) {
final ObservableSatellite satellite = observed.getSatellites().get(i);
states[i] = interpolators.get(satellite.getPropagatorIndex()).getInterpolatedState(next.getDate());
}
final EstimatedMeasurement<?> estimated = observed.estimate(model.getIterationsCount(),
model.getEvaluationsCount(),
states);
// fetch the evaluated measurement to the estimator
model.fetchEvaluatedMeasurement(index, estimated);
// prepare handling of next measurement
++number;
index += observed.getDimension();
}
}
}