RangeRateTroposphericDelayModifier.java
- /* Copyright 2002-2024 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
- * limitations under the License.
- */
- package org.orekit.estimation.measurements.modifiers;
- import org.hipparchus.CalculusFieldElement;
- import org.orekit.attitudes.FrameAlignedProvider;
- 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.RangeRate;
- import org.orekit.models.earth.troposphere.DiscreteTroposphericModel;
- import org.orekit.propagation.FieldSpacecraftState;
- import org.orekit.propagation.SpacecraftState;
- /** Class modifying theoretical range-rate measurements with tropospheric delay.
- * The effect of tropospheric correction on the range-rate is directly computed
- * through the computation of the tropospheric delay difference with respect to
- * time.
- *
- * In general, for GNSS, VLBI, ... there is hardly any frequency dependence in the delay.
- * For SLR techniques however, the frequency dependence is sensitive.
- *
- * @author Joris Olympio
- * @since 8.0
- */
- public class RangeRateTroposphericDelayModifier extends BaseRangeRateTroposphericDelayModifier implements EstimationModifier<RangeRate> {
- /** Two-way measurement factor. */
- private final double fTwoWay;
- /** Constructor.
- *
- * @param model Tropospheric delay model appropriate for the current range-rate measurement method.
- * @param tw Flag indicating whether the measurement is two-way.
- */
- public RangeRateTroposphericDelayModifier(final DiscreteTroposphericModel model, final boolean tw) {
- super(model);
- if (tw) {
- fTwoWay = 2.;
- } else {
- fTwoWay = 1.;
- }
- }
- /** Compute the measurement error due to Troposphere.
- * @param station station
- * @param state spacecraft state
- * @return the measurement error due to Troposphere
- */
- @Override
- public double rangeRateErrorTroposphericModel(final GroundStation station,
- final SpacecraftState state) {
- return fTwoWay * super.rangeRateErrorTroposphericModel(station, state);
- }
- /** Compute the measurement error due to Troposphere.
- * @param <T> type of the element
- * @param station station
- * @param state spacecraft state
- * @param parameters tropospheric model parameters
- * @return the measurement error due to Troposphere
- */
- @Override
- public <T extends CalculusFieldElement<T>> T rangeRateErrorTroposphericModel(final GroundStation station,
- final FieldSpacecraftState<T> state,
- final T[] parameters) {
- return super.rangeRateErrorTroposphericModel(station, state, parameters).multiply(fTwoWay);
- }
- /** {@inheritDoc} */
- @Override
- public void modifyWithoutDerivatives(final EstimatedMeasurementBase<RangeRate> estimated) {
- final RangeRate measurement = estimated.getObservedMeasurement();
- final GroundStation station = measurement.getStation();
- RangeRateModifierUtil.modifyWithoutDerivatives(estimated, station, this::rangeRateErrorTroposphericModel);
- }
- /** {@inheritDoc} */
- @Override
- public void modify(final EstimatedMeasurement<RangeRate> estimated) {
- final RangeRate measurement = estimated.getObservedMeasurement();
- final GroundStation station = measurement.getStation();
- final SpacecraftState state = estimated.getStates()[0];
- RangeRateModifierUtil.modify(estimated, getTropoModel(),
- new ModifierGradientConverter(state, 6, new FrameAlignedProvider(state.getFrame())),
- station,
- this::rangeRateErrorTroposphericModel,
- this::rangeRateErrorTroposphericModel);
- }
- }