MeasurementBuilder.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
* (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,
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package org.orekit.estimation.measurements.generation;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.orekit.estimation.measurements.EstimationModifier;
import org.orekit.estimation.measurements.ObservableSatellite;
import org.orekit.estimation.measurements.ObservedMeasurement;
import org.orekit.propagation.SpacecraftState;
import org.orekit.propagation.sampling.OrekitStepInterpolator;
import org.orekit.time.AbsoluteDate;
/** Interface for generating individual {@link ObservedMeasurement measurements}.
* @param <T> the type of the measurement
* @author Luc Maisonobe
* @since 9.3
*/
public interface MeasurementBuilder<T extends ObservedMeasurement<T>> {
/** Initialize builder at the start of a measurements generation.
* <p>
* This method is called once at the start of the measurements generation. It
* may be used by the builder to initialize some internal data
* if needed, typically setting up parameters reference dates.
* </p>
* @param start start of the measurements time span
* @param end end of the measurements time span
*/
void init(AbsoluteDate start, AbsoluteDate end);
/** Add a modifier.
* @param modifier modifier to add
*/
void addModifier(EstimationModifier<T> modifier);
/** Get the modifiers that apply to a measurement.
* @return modifiers that apply to a measurement
* @see #addModifier(EstimationModifier)
*/
List<EstimationModifier<T>> getModifiers();
/** Get the satellites related to this measurement.
* @return satellites related to this measurement
* @since 12.0
*/
ObservableSatellite[] getSatellites();
/** Generate a single measurement.
* @param date measurement date
* @param interpolators interpolators relevant for this builder
* @return generated measurement
* @since 12.0
*/
T build(AbsoluteDate date, Map<ObservableSatellite, OrekitStepInterpolator> interpolators);
/** Generate a single measurement.<p>
*
* Warning: This method uses "shiftedBy" so it is not as accurate as the method above that uses interpolators.
*
* @param date measurement date
* @param states all spacecraft states (i.e. including ones that may not be relevant for the current builder)
* @return generated measurement
* @since 12.1
*/
default T build(AbsoluteDate date, SpacecraftState[] states) {
final Map<ObservableSatellite, OrekitStepInterpolator> interpolators = new ConcurrentHashMap<>();
for (int i = 0; i < states.length; i++) {
final ObservableSatellite sat = getSatellites()[i];
final SpacecraftState state = states[i];
final OrekitStepInterpolator interpolator = new OrekitStepInterpolator() {
/** {@inheritDoc} */
@Override
public OrekitStepInterpolator restrictStep(final SpacecraftState newPreviousState, final SpacecraftState newCurrentState) {
return null;
}
/** {@inheritDoc} */
@Override
public boolean isPreviousStateInterpolated() {
return false;
}
/** {@inheritDoc} */
@Override
public boolean isForward() {
return true;
}
/** {@inheritDoc} */
@Override
public boolean isCurrentStateInterpolated() {
return false;
}
/** {@inheritDoc} */
@Override
public SpacecraftState getPreviousState() {
return state;
}
/** {@inheritDoc} */
@Override
public SpacecraftState getInterpolatedState(final AbsoluteDate date) {
return state.shiftedBy(date.durationFrom(state));
}
/** {@inheritDoc} */
@Override
public SpacecraftState getCurrentState() {
return state;
}
};
interpolators.put(sat, interpolator);
}
return build( date, interpolators);
}
}