PhaseCentersOneWayGNSSBaseModifier.java
- /* Copyright 2002-2024 Thales Alenia Space
- * 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.orekit.attitudes.AttitudeProvider;
- import org.orekit.estimation.measurements.AbstractMeasurement;
- import org.orekit.estimation.measurements.EstimatedMeasurementBase;
- import org.orekit.frames.StaticTransform;
- import org.orekit.gnss.antenna.FrequencyPattern;
- import org.orekit.orbits.CartesianOrbit;
- import org.orekit.orbits.Orbit;
- import org.orekit.propagation.SpacecraftState;
- import org.orekit.time.AbsoluteDate;
- import org.orekit.utils.TimeStampedPVCoordinates;
- /** On-board antenna offset effect on inter-satellites phase measurements.
- * @param <T> type of the measurement
- * @author Luc Maisonobe
- * @since 12.1
- */
- public class PhaseCentersOneWayGNSSBaseModifier<T extends AbstractMeasurement<T>> {
- /** Link offset model. */
- private final PhaseCentersOffsetComputer link;
- /** Attitude provider of the emitting satellite. */
- private final AttitudeProvider attitudeProvider;
- /** Simple constructor.
- * @param receiverPattern pattern for receiver satellite
- * @param emitterPattern pattern for emitter satellite
- * @param attitudeProvider attitude provider of the emitting satellite
- */
- public PhaseCentersOneWayGNSSBaseModifier(final FrequencyPattern receiverPattern,
- final FrequencyPattern emitterPattern,
- final AttitudeProvider attitudeProvider) {
- this.link = new PhaseCentersOffsetComputer(emitterPattern, receiverPattern);
- this.attitudeProvider = attitudeProvider;
- }
- /** Compute distance modification for one way measurement.
- * @param estimated estimated measurement to modify
- * @return distance modification to add to raw measurement
- */
- public double oneWayDistanceModification(final EstimatedMeasurementBase<T> estimated) {
- // The participants are remote satellite at emission, local satellite at reception
- final TimeStampedPVCoordinates[] phaseParticipants = estimated.getParticipants();
- final AbsoluteDate phaseEmissionDate = phaseParticipants[0].getDate();
- final AbsoluteDate phaseReceptionDate = phaseParticipants[1].getDate();
- // Transforms from spacecraft to inertial frame at reception date
- final SpacecraftState refStateLocal = estimated.getStates()[0];
- final SpacecraftState receptionState = refStateLocal.shiftedBy(phaseReceptionDate.durationFrom(refStateLocal.getDate()));
- final StaticTransform receptionSpacecraftToInert = receptionState.toStaticTransform().getInverse();
- // Orbit of the remote satellite
- final Orbit orbitRemote = new CartesianOrbit(phaseParticipants[0], refStateLocal.getFrame(), receptionState.getMu());
- // Transforms from spacecraft to inertial frame at emission date
- final SpacecraftState refStateRemote = new SpacecraftState(orbitRemote,
- attitudeProvider.getAttitude(orbitRemote,
- orbitRemote.getDate(),
- orbitRemote.getFrame()));
- final SpacecraftState emissionState = refStateRemote.shiftedBy(phaseEmissionDate.durationFrom(refStateRemote.getDate()));
- final StaticTransform emissionSpacecraftToInert = emissionState.toStaticTransform().getInverse();
- // compute offset due to phase centers
- return link.offset(emissionSpacecraftToInert, receptionSpacecraftToInert);
- }
- }