TDOAModifierUtil.java
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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
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* Unless required by applicable law or agreed to in writing, software
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package org.orekit.estimation.measurements.modifiers;
import java.util.Arrays;
import org.hipparchus.analysis.differentiation.Gradient;
import org.orekit.estimation.measurements.EstimatedMeasurement;
import org.orekit.estimation.measurements.EstimatedMeasurementBase;
import org.orekit.estimation.measurements.EstimationModifier;
import org.orekit.estimation.measurements.GroundStation;
import org.orekit.estimation.measurements.ObservedMeasurement;
import org.orekit.propagation.FieldSpacecraftState;
import org.orekit.propagation.SpacecraftState;
import org.orekit.propagation.integration.AbstractGradientConverter;
import org.orekit.utils.Differentiation;
import org.orekit.utils.ParameterDriver;
import org.orekit.utils.ParameterDriversProvider;
import org.orekit.utils.TimeSpanMap.Span;
/** Utility class for TDOA measurements.
* @author Pascal Parraud
* @since 11.2
*/
class TDOAModifierUtil {
/** Private constructor for utility class.*/
private TDOAModifierUtil() {
// not used
}
/** Apply a modifier to an estimated measurement.
* @param <T> type of the measurement
* @param estimated estimated measurement to modify
* @param primeStation prime station
* @param secondStation second station
* @param modelEffect model effect
* @deprecated as of 12.1, replaced by {@link #modifyWithoutDerivatives(EstimatedMeasurementBase,
* GroundStation, GroundStation, ParametricModelEffect, EstimationModifier)}
*/
@Deprecated
public static <T extends ObservedMeasurement<T>> void modifyWithoutDerivatives(final EstimatedMeasurementBase<T> estimated,
final GroundStation primeStation,
final GroundStation secondStation,
final ParametricModelEffect modelEffect) {
modifyWithoutDerivatives(estimated, primeStation, secondStation, modelEffect, null);
}
/** Apply a modifier to an estimated measurement.
* @param <T> type of the measurement
* @param estimated estimated measurement to modify
* @param primeStation prime station
* @param secondStation second station
* @param modelEffect model effect
* @param modifier applied modifier
* @since 12.1
*/
public static <T extends ObservedMeasurement<T>> void modifyWithoutDerivatives(final EstimatedMeasurementBase<T> estimated,
final GroundStation primeStation,
final GroundStation secondStation,
final ParametricModelEffect modelEffect,
final EstimationModifier<T> modifier) {
final SpacecraftState state = estimated.getStates()[0];
final double[] oldValue = estimated.getEstimatedValue();
final double primeDelay = modelEffect.evaluate(primeStation, state);
final double secondDelay = modelEffect.evaluate(secondStation, state);
// Update estimated value taking into account the ionospheric delay for each downlink.
// The ionospheric time delay is directly applied to the TDOA.
final double[] newValue = oldValue.clone();
newValue[0] += primeDelay;
newValue[0] -= secondDelay;
estimated.modifyEstimatedValue(modifier, newValue);
}
/** Apply a modifier to an estimated measurement.
* @param <T> type of the measurement
* @param estimated estimated measurement to modify
* @param primeStation prime station
* @param secondStation second station
* @param converter gradient converter
* @param parametricModel parametric modifier model
* @param modelEffect model effect
* @param modelEffectGradient model effect gradient
* @deprecated as of 12.1, replaced by {@link #modify(EstimatedMeasurement,
* ParameterDriversProvider, AbstractGradientConverter, GroundStation, GroundStation,
* ParametricModelEffect, ParametricModelEffectGradient, EstimationModifier)}
*/
@Deprecated
public static <T extends ObservedMeasurement<T>> void modify(final EstimatedMeasurement<T> estimated,
final ParameterDriversProvider parametricModel,
final AbstractGradientConverter converter,
final GroundStation primeStation, final GroundStation secondStation,
final ParametricModelEffect modelEffect,
final ParametricModelEffectGradient modelEffectGradient) {
modify(estimated, parametricModel, converter, primeStation, secondStation,
modelEffect, modelEffectGradient, null);
}
/** Apply a modifier to an estimated measurement.
* @param <T> type of the measurement
* @param estimated estimated measurement to modify
* @param primeStation prime station
* @param secondStation second station
* @param converter gradient converter
* @param parametricModel parametric modifier model
* @param modelEffect model effect
* @param modelEffectGradient model effect gradient
* @param modifier applied modifier
* @since 12.1
*/
public static <T extends ObservedMeasurement<T>> void modify(final EstimatedMeasurement<T> estimated,
final ParameterDriversProvider parametricModel,
final AbstractGradientConverter converter,
final GroundStation primeStation, final GroundStation secondStation,
final ParametricModelEffect modelEffect,
final ParametricModelEffectGradient modelEffectGradient,
final EstimationModifier<T> modifier) {
final SpacecraftState state = estimated.getStates()[0];
final double[] oldValue = estimated.getEstimatedValue();
// Update estimated derivatives with Jacobian of the measure wrt state
final FieldSpacecraftState<Gradient> gState = converter.getState(parametricModel);
final Gradient[] gParameters = converter.getParameters(gState, parametricModel);
final Gradient primeGDelay = modelEffectGradient.evaluate(primeStation, gState, gParameters);
final Gradient secondGDelay = modelEffectGradient.evaluate(secondStation, gState, gParameters);
final double[] primeDerivatives = primeGDelay.getGradient();
final double[] secondDerivatives = secondGDelay.getGradient();
final double[][] stateDerivatives = estimated.getStateDerivatives(0);
for (int jcol = 0; jcol < stateDerivatives[0].length; ++jcol) {
stateDerivatives[0][jcol] += primeDerivatives[jcol];
stateDerivatives[0][jcol] -= secondDerivatives[jcol];
}
estimated.setStateDerivatives(0, stateDerivatives);
int index = 0;
for (final ParameterDriver driver : parametricModel.getParametersDrivers()) {
if (driver.isSelected()) {
for (Span<String> span = driver.getNamesSpanMap().getFirstSpan(); span != null; span = span.next()) {
// update estimated derivatives with derivative of the modification wrt ionospheric parameters
double parameterDerivative = estimated.getParameterDerivatives(driver, span.getStart())[0];
parameterDerivative += primeDerivatives[index + converter.getFreeStateParameters()];
parameterDerivative -= secondDerivatives[index + converter.getFreeStateParameters()];
estimated.setParameterDerivatives(driver, span.getStart(), parameterDerivative);
index += 1;
}
}
}
// Update derivatives with respect to primary station position
for (final ParameterDriver driver : Arrays.asList(primeStation.getClockOffsetDriver(),
primeStation.getEastOffsetDriver(),
primeStation.getNorthOffsetDriver(),
primeStation.getZenithOffsetDriver())) {
if (driver.isSelected()) {
for (Span<String> span = driver.getNamesSpanMap().getFirstSpan(); span != null; span = span.next()) {
double parameterDerivative = estimated.getParameterDerivatives(driver, span.getStart())[0];
parameterDerivative += Differentiation.differentiate((d, t) -> modelEffect.evaluate(primeStation, state),
3, 10.0 * driver.getScale()).value(driver, state.getDate());
estimated.setParameterDerivatives(driver, span.getStart(), parameterDerivative);
}
}
}
// Update derivatives with respect to secondary station position
for (final ParameterDriver driver : Arrays.asList(secondStation.getClockOffsetDriver(),
secondStation.getEastOffsetDriver(),
secondStation.getNorthOffsetDriver(),
secondStation.getZenithOffsetDriver())) {
if (driver.isSelected()) {
for (Span<String> span = driver.getNamesSpanMap().getFirstSpan(); span != null; span = span.next()) {
double parameterDerivative = estimated.getParameterDerivatives(driver, span.getStart())[0];
parameterDerivative -= Differentiation.differentiate((d, t) -> modelEffect.evaluate(secondStation, state),
3, 10.0 * driver.getScale()).value(driver, state.getDate());
estimated.setParameterDerivatives(driver, span.getStart(), parameterDerivative);
}
}
}
// Update estimated value taking into account the ionospheric delay for each downlink.
// The ionospheric time delay is directly applied to the TDOA.
final double[] newValue = oldValue.clone();
newValue[0] += primeGDelay.getReal();
newValue[0] -= secondGDelay.getReal();
estimated.modifyEstimatedValue(modifier, newValue);
}
}