EphemerisSegmentAttitudeProvider.java
- /* Copyright 2002-2020 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.files.general;
- import java.util.List;
- import java.util.stream.Collectors;
- import org.hipparchus.RealFieldElement;
- import org.orekit.attitudes.Attitude;
- import org.orekit.attitudes.AttitudeProvider;
- import org.orekit.attitudes.BoundedAttitudeProvider;
- import org.orekit.attitudes.FieldAttitude;
- import org.orekit.files.general.AttitudeEphemerisFile.AttitudeEphemerisSegment;
- import org.orekit.frames.Frame;
- import org.orekit.time.AbsoluteDate;
- import org.orekit.time.FieldAbsoluteDate;
- import org.orekit.utils.FieldPVCoordinatesProvider;
- import org.orekit.utils.ImmutableTimeStampedCache;
- import org.orekit.utils.PVCoordinatesProvider;
- import org.orekit.utils.TimeStampedAngularCoordinates;
- import org.orekit.utils.TimeStampedFieldAngularCoordinates;
- /**
- * An {@link AttitudeProvider} based on an {@link AttitudeEphemerisSegment}.
- * @author Bryan Cazabonne
- * @since 10.3
- */
- public class EphemerisSegmentAttitudeProvider implements BoundedAttitudeProvider {
- /** Cached attitude table. */
- private final transient ImmutableTimeStampedCache<TimeStampedAngularCoordinates> table;
- /** Tabular data from which this attitude provider is built. */
- private final AttitudeEphemerisSegment segment;
- /**
- * Constructor.
- * @param segment segment containing the attitude data for this provider.
- */
- public EphemerisSegmentAttitudeProvider(final AttitudeEphemerisSegment segment) {
- this.segment = segment;
- this.table = new ImmutableTimeStampedCache<TimeStampedAngularCoordinates>(segment.getInterpolationSamples(),
- segment.getAngularCoordinates());
- }
- /** {@inheritDoc} */
- @Override
- public Attitude getAttitude(final PVCoordinatesProvider pvProv, final AbsoluteDate date,
- final Frame frame) {
- // Get attitudes sample on which interpolation will be performed
- final List<TimeStampedAngularCoordinates> attitudeSample = table.getNeighbors(date).collect(Collectors.toList());
- // Interpolate attitude data
- final TimeStampedAngularCoordinates interpolatedAttitude =
- TimeStampedAngularCoordinates.interpolate(date, segment.getAvailableDerivatives(), attitudeSample);
- // Build the interpolated attitude
- return new Attitude(segment.getReferenceFrame(), interpolatedAttitude);
- }
- /** {@inheritDoc} */
- @Override
- public <T extends RealFieldElement<T>> FieldAttitude<T> getAttitude(final FieldPVCoordinatesProvider<T> pvProv,
- final FieldAbsoluteDate<T> date, final Frame frame) {
- // Get attitudes sample on which interpolation will be performed
- final List<TimeStampedFieldAngularCoordinates<T>> attitudeSample = table.getNeighbors(date.toAbsoluteDate()).
- map(ac -> new TimeStampedFieldAngularCoordinates<>(date.getField(), ac)).
- collect(Collectors.toList());
- // Interpolate attitude data
- final TimeStampedFieldAngularCoordinates<T> interpolatedAttitude =
- TimeStampedFieldAngularCoordinates.interpolate(date, segment.getAvailableDerivatives(), attitudeSample);
- // Build the interpolated attitude
- return new FieldAttitude<>(segment.getReferenceFrame(), interpolatedAttitude);
- }
- /** {@inheritDoc} */
- @Override
- public AbsoluteDate getMinDate() {
- return segment.getStart();
- }
- /** {@inheritDoc} */
- @Override
- public AbsoluteDate getMaxDate() {
- return segment.getStop();
- }
- }