EstimatedMeasurement.java
/* Copyright 2002-2021 CS GROUP
* 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.
* 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,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
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*/
package org.orekit.estimation.measurements;
import java.util.IdentityHashMap;
import java.util.Map;
import java.util.stream.Stream;
import org.orekit.errors.OrekitIllegalArgumentException;
import org.orekit.errors.OrekitMessages;
import org.orekit.propagation.SpacecraftState;
import org.orekit.time.AbsoluteDate;
import org.orekit.utils.ParameterDriver;
import org.orekit.utils.TimeStampedPVCoordinates;
/** Class holding an estimated theoretical value associated to an {@link ObservedMeasurement observed measurement}.
* @param <T> the type of the measurement
* @author Luc Maisonobe
* @since 8.0
*/
public class EstimatedMeasurement<T extends ObservedMeasurement<T>> implements ComparableMeasurement {
/** Associated observed measurement. */
private final T observedMeasurement;
/** Iteration number. */
private final int iteration;
/** Evaluations counter. */
private final int count;
/** States of the spacecrafts. */
private final SpacecraftState[] states;
/** Coordinates of the participants in signal travel order. */
private final TimeStampedPVCoordinates[] participants;
/** Estimated value. */
private double[] estimatedValue;
/** Measurement status. */
private Status status;
/** Partial derivatives with respect to states. */
private double[][][] stateDerivatives;
/** Partial derivatives with respect to parameters. */
private final Map<ParameterDriver, double[]> parametersDerivatives;
/** Simple constructor.
* @param observedMeasurement associated observed measurement
* @param iteration iteration number
* @param count evaluations counter
* @param states states of the spacecrafts
* @param participants coordinates of the participants in signal travel order
* in inertial frame
*/
public EstimatedMeasurement(final T observedMeasurement,
final int iteration, final int count,
final SpacecraftState[] states,
final TimeStampedPVCoordinates[] participants) {
this.observedMeasurement = observedMeasurement;
this.iteration = iteration;
this.count = count;
this.states = states.clone();
this.participants = participants.clone();
this.status = Status.PROCESSED;
this.stateDerivatives = new double[states.length][][];
this.parametersDerivatives = new IdentityHashMap<ParameterDriver, double[]>();
}
/** Get the associated observed measurement.
* @return associated observed measurement
*/
public T getObservedMeasurement() {
return observedMeasurement;
}
/** {@inheritDoc} */
@Override
public AbsoluteDate getDate() {
return observedMeasurement.getDate();
}
/** Get the iteration number.
* @return iteration number
*/
public int getIteration() {
return iteration;
}
/** Get the evaluations counter.
* @return evaluations counter
*/
public int getCount() {
return count;
}
/** Get the states of the spacecrafts.
* @return states of the spacecrafts
*/
public SpacecraftState[] getStates() {
return states.clone();
}
/** Get the coordinates of the measurements participants in signal travel order.
* <p>
* First participant (at index 0) emits the signal (it is for example a ground
* station for two-way range measurement). Last participant receives the signal
* (it is also the ground station for two-way range measurement, but a few
* milliseconds later). Intermediate participants relfect the signal (it is the
* spacecraft for two-way range measurement).
* </p>
* @return coordinates of the measurements participants in signal travel order
* in inertial frame
*/
public TimeStampedPVCoordinates[] getParticipants() {
return participants.clone();
}
/** Get the time offset from first state date to measurement date.
* @return time offset from first state date to measurement date
*/
public double getTimeOffset() {
return observedMeasurement.getDate().durationFrom(states[0].getDate());
}
/** {@inheritDoc} */
@Override
public double[] getObservedValue() {
return observedMeasurement.getObservedValue();
}
/** Get the estimated value.
* @return estimated value
*/
public double[] getEstimatedValue() {
return estimatedValue.clone();
}
/** Set the estimated value.
* @param estimatedValue estimated value
*/
public void setEstimatedValue(final double... estimatedValue) {
this.estimatedValue = estimatedValue.clone();
}
/** Get the status.
* <p>
* The status is set to {@link Status#PROCESSED PROCESSED} at construction, and
* can be reset to {@link Status#REJECTED REJECTED} later on, typically by
* {@link org.orekit.estimation.measurements.modifiers.OutlierFilter OutlierFilter}
* or {@link org.orekit.estimation.measurements.modifiers.DynamicOutlierFilter DynamicOutlierFilter}
* </p>
* @return status
*/
public Status getStatus() {
return status;
}
/** Set the status.
* @param status status to set
*/
public void setStatus(final Status status) {
this.status = status;
}
/** Get state size.
* <p>
* Warning, the {@link #setStateDerivatives(int, double[][])}
* method must have been called before this method is called.
* </p>
* @return state size
* @since 10.1
*/
public int getStateSize() {
return stateDerivatives[0][0].length;
}
/** Get the partial derivatives of the {@link #getEstimatedValue()
* simulated measurement} with respect to state Cartesian coordinates.
* @param index index of the state, according to the {@code states}
* passed at construction
* @return partial derivatives of the simulated value (array of size
* {@link ObservedMeasurement#getDimension() dimension} x 6)
*/
public double[][] getStateDerivatives(final int index) {
final double[][] sd = new double[observedMeasurement.getDimension()][];
for (int i = 0; i < observedMeasurement.getDimension(); ++i) {
sd[i] = stateDerivatives[index][i].clone();
}
return sd;
}
/** Set the partial derivatives of the {@link #getEstimatedValue()
* simulated measurement} with respect to state Cartesian coordinates.
* @param index index of the state, according to the {@code states}
* passed at construction
* @param derivatives partial derivatives with respect to state
*/
public void setStateDerivatives(final int index, final double[]... derivatives) {
this.stateDerivatives[index] = new double[observedMeasurement.getDimension()][];
for (int i = 0; i < observedMeasurement.getDimension(); ++i) {
this.stateDerivatives[index][i] = derivatives[i].clone();
}
}
/** Get all the drivers with set derivatives.
* @return all the drivers with set derivatives
* @since 9.0
*/
public Stream<ParameterDriver> getDerivativesDrivers() {
return parametersDerivatives.entrySet().stream().map(entry -> entry.getKey());
}
/** Get the partial derivatives of the {@link #getEstimatedValue()
* simulated measurement} with respect to a parameter.
* @param driver driver for the parameter
* @return partial derivatives of the simulated value
* @exception OrekitIllegalArgumentException if parameter is unknown
*/
public double[] getParameterDerivatives(final ParameterDriver driver)
throws OrekitIllegalArgumentException {
final double[] p = parametersDerivatives.get(driver);
if (p == null) {
final StringBuilder builder = new StringBuilder();
for (final Map.Entry<ParameterDriver, double[]> entry : parametersDerivatives.entrySet()) {
if (builder.length() > 0) {
builder.append(", ");
}
builder.append(entry.getKey().getName());
}
throw new OrekitIllegalArgumentException(OrekitMessages.UNSUPPORTED_PARAMETER_NAME,
driver.getName(),
builder.length() > 0 ? builder.toString() : "<none>");
}
return p;
}
/** Set the partial derivatives of the {@link #getEstimatedValue()
* simulated measurement} with respect to parameter.
* @param driver driver for the parameter
* @param parameterDerivatives partial derivatives with respect to parameter
*/
public void setParameterDerivatives(final ParameterDriver driver, final double... parameterDerivatives) {
parametersDerivatives.put(driver, parameterDerivatives);
}
/** Enumerate for the status of the measurement. */
public enum Status {
/** Status for processed measurements. */
PROCESSED,
/** Status for rejected measurements. */
REJECTED;
}
}