RangeRateModifierUtil.java
/* Copyright 2002-2022 CS GROUP
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* 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
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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.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.ParametersDriversProvider;
/** Utility class modifying theoretical range-rate measurement.
* @author Joris Olympio
* @since 11.2
*/
public class RangeRateModifierUtil {
/** Private constructor for utility class.*/
private RangeRateModifierUtil() {
// not used
}
/** Apply a modifier to an estimated measurement.
* @param <T> type of the measurement
* @param estimated estimated measurement to modify
* @param station ground station
* @param converter gradient converter
* @param parametricModel parametric modifier model
* @param modelEffect model effect
* @param modelEffectGradient model effect gradient
*/
public static <T extends ObservedMeasurement<T>> void modify(final EstimatedMeasurement<T> estimated,
final ParametersDriversProvider parametricModel,
final AbstractGradientConverter converter,
final GroundStation station,
final ParametricModelEffect modelEffect,
final ParametricModelEffectGradient modelEffectGradient) {
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 gDelay = modelEffectGradient.evaluate(station, gState, gParameters);
final double[] derivatives = gDelay.getGradient();
// update estimated derivatives with Jacobian of the measure wrt state
final double[][] stateDerivatives = estimated.getStateDerivatives(0);
for (int jcol = 0; jcol < stateDerivatives[0].length; ++jcol) {
stateDerivatives[0][jcol] += derivatives[jcol];
}
estimated.setStateDerivatives(0, stateDerivatives);
int index = 0;
for (final ParameterDriver driver : parametricModel.getParametersDrivers()) {
if (driver.isSelected()) {
// update estimated derivatives with derivative of the modification wrt ionospheric parameters
double parameterDerivative = estimated.getParameterDerivatives(driver)[0];
parameterDerivative += derivatives[index + converter.getFreeStateParameters()];
estimated.setParameterDerivatives(driver, parameterDerivative);
index = index + 1;
}
}
for (final ParameterDriver driver : Arrays.asList(station.getClockOffsetDriver(),
station.getEastOffsetDriver(),
station.getNorthOffsetDriver(),
station.getZenithOffsetDriver())) {
if (driver.isSelected()) {
// update estimated derivatives with derivative of the modification wrt station parameters
double parameterDerivative = estimated.getParameterDerivatives(driver)[0];
parameterDerivative += Differentiation.differentiate(d -> modelEffect.evaluate(station, state),
3, 10.0 * driver.getScale()).value(driver);
estimated.setParameterDerivatives(driver, parameterDerivative);
}
}
// update estimated value taking into account the ionospheric delay.
// The ionospheric delay is directly added to the range.
final double[] newValue = oldValue.clone();
newValue[0] = newValue[0] + gDelay.getValue();
estimated.setEstimatedValue(newValue);
}
}