OrekitAttitudeEphemerisFile.java
/* Copyright 2002-2021 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
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*/
package org.orekit.files.general;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.orekit.attitudes.BoundedAttitudeProvider;
import org.orekit.attitudes.FixedFrameBuilder;
import org.orekit.attitudes.TabulatedProvider;
import org.orekit.errors.OrekitIllegalArgumentException;
import org.orekit.errors.OrekitMessages;
import org.orekit.frames.Frame;
import org.orekit.propagation.SpacecraftState;
import org.orekit.time.AbsoluteDate;
import org.orekit.utils.AngularDerivativesFilter;
import org.orekit.utils.TimeStampedAngularCoordinates;
/**
* A class for encapsulating Orekit propagators within an {@link AttitudeEphemerisFile}
* complaint object that makes for easy serialization to external ephemeris
* formats like AEM.
*
* @author Raphaël Fermé
* @since 10.3
*
*/
public class OrekitAttitudeEphemerisFile
implements AttitudeEphemerisFile<TimeStampedAngularCoordinates,
OrekitAttitudeEphemerisFile.OrekitAttitudeEphemerisSegment> {
/** Hashmap of satellite ephemeris. **/
private final Map<String, OrekitSatelliteAttitudeEphemeris> satellites;
/**
* Standard default constructor.
*/
public OrekitAttitudeEphemerisFile() {
this.satellites = new ConcurrentHashMap<>();
}
/** {@inheritDoc} */
@Override
public Map<String, OrekitSatelliteAttitudeEphemeris> getSatellites() {
return Collections.unmodifiableMap(satellites);
}
/**
* Adds a new satellite to this object.
*
* @param id
* ID to use for this satellite
* @return the new satellite object
*/
public OrekitSatelliteAttitudeEphemeris addSatellite(final String id) {
final OrekitSatelliteAttitudeEphemeris newSat = new OrekitSatelliteAttitudeEphemeris(id);
this.satellites.put(id, newSat);
return newSat;
}
/**
* Inner class of {@link OrekitAttitudeEphemerisFile} that defines the
* {@link OrekitSatelliteAttitudeEphemeris} corresponding object for this ephemeris type.
*
*/
public static class OrekitSatelliteAttitudeEphemeris
implements SatelliteAttitudeEphemeris<TimeStampedAngularCoordinates,
OrekitAttitudeEphemerisFile.OrekitAttitudeEphemerisSegment> {
/** Default interpolation sample size if it is not specified. **/
public static final String DEFAULT_INTERPOLATION_METHOD = "LINEAR";
/** Default interpolation sample size if it is not specified. **/
public static final int DEFAULT_INTERPOLATION_SIZE = 2;
/** ID of the space object encapsulated here. **/
private final String id;
/** Earliest date of this file. **/
private AbsoluteDate startDate;
/** Latest date of this file. **/
private AbsoluteDate stopDate;
/** List of segments in the file. **/
private final List<OrekitAttitudeEphemerisSegment> segments;
/**
* Standard constructor for building the satellite Ephemeris object.
*
* @param id
* the ID of the space object for this data
*/
public OrekitSatelliteAttitudeEphemeris(final String id) {
this.id = id;
this.segments = new ArrayList<>();
}
/** {@inheritDoc} */
@Override
public String getId() {
return id;
}
/** {@inheritDoc} */
@Override
public List<OrekitAttitudeEphemerisSegment> getSegments() {
return Collections.unmodifiableList(this.segments);
}
/** {@inheritDoc} */
@Override
public AbsoluteDate getStart() {
return this.startDate;
}
/** {@inheritDoc} */
@Override
public AbsoluteDate getStop() {
return this.stopDate;
}
/**
* Injects pre-computed satellite states into this attitude ephemeris file
* object, returning the generated {@link OrekitAttitudeEphemerisSegment} that
* has been stored internally.
*
* @param states
* a list of {@link SpacecraftState} that will comprise this
* new unit
* @param interpolationMethod
* the interpolation method that should be used when processed
* by another system
* @param interpolationSamples
* the number of interpolation samples that should be used
* when processed by another system
* @param availableDerivatives derivatives to use for interpolation
* @return the generated {@link OrekitAttitudeEphemerisSegment}
*/
public OrekitAttitudeEphemerisSegment addNewSegment(final List<SpacecraftState> states,
final String interpolationMethod,
final int interpolationSamples,
final AngularDerivativesFilter availableDerivatives) {
final int minimumSampleSize = 2;
if (states == null || states.size() == 0) {
throw new OrekitIllegalArgumentException(OrekitMessages.NULL_ARGUMENT, "states");
}
if (interpolationSamples < minimumSampleSize) {
throw new OrekitIllegalArgumentException(OrekitMessages.NOT_ENOUGH_DATA_FOR_INTERPOLATION,
interpolationSamples);
}
final AbsoluteDate start = states.get(0).getDate();
final AbsoluteDate stop = states.get(states.size() - 1).getDate();
if (this.startDate == null || start.compareTo(this.startDate) < 0) {
this.startDate = start;
}
if (this.stopDate == null || stop.compareTo(this.stopDate) > 0) {
this.stopDate = stop;
}
final List<TimeStampedAngularCoordinates> attitudeDataLines = new ArrayList<>();
for (SpacecraftState state : states) {
attitudeDataLines.add(state.getAttitude().getOrientation());
}
final OrekitAttitudeEphemerisSegment newSeg =
new OrekitAttitudeEphemerisSegment(attitudeDataLines, interpolationMethod, interpolationSamples,
states.get(0).getFrame(), availableDerivatives);
this.segments.add(newSeg);
return newSeg;
}
}
public static class OrekitAttitudeEphemerisSegment
implements AttitudeEphemerisFile.AttitudeEphemerisSegment<TimeStampedAngularCoordinates> {
/** List of attitude data lines. */
private List<TimeStampedAngularCoordinates> attitudeDataLines;
/** The interpolation method to be used. */
private String interpolationMethod;
/** The number of interpolation samples. */
private int interpolationSamples;
/** Enumerate for selecting which derivatives to use in {@link #attitudeDataLines} interpolation. */
private AngularDerivativesFilter availableDerivatives;
/** Reference frame from which attitude is defined. */
private Frame referenceFrame;
/**
* Constructor for OrekitAttitudeEphemerisSegment.
*
* @param attitudeDataLines
* attitude data lines for this segment.
* @param interpolationMethod
* the interpolation method to use.
* @param interpolationSamples
* the number of samples to use during interpolation.
* @param referenceFrame
* reference frame from which the attitude is defined
* @param availableDerivatives derivatives to use for interpolation
*/
public OrekitAttitudeEphemerisSegment(final List<TimeStampedAngularCoordinates> attitudeDataLines,
final String interpolationMethod,
final int interpolationSamples,
final Frame referenceFrame,
final AngularDerivativesFilter availableDerivatives) {
this.attitudeDataLines = attitudeDataLines;
this.interpolationMethod = interpolationMethod;
this.interpolationSamples = interpolationSamples;
this.referenceFrame = referenceFrame;
this.availableDerivatives = availableDerivatives;
}
/** {@inheritDoc} */
@Override
public List<TimeStampedAngularCoordinates> getAngularCoordinates() {
return Collections.unmodifiableList(attitudeDataLines);
}
/** {@inheritDoc} */
@Override
public Frame getReferenceFrame() {
return referenceFrame;
}
/** {@inheritDoc} */
@Override
public AbsoluteDate getStart() {
return attitudeDataLines.get(0).getDate();
}
/** {@inheritDoc} */
@Override
public AbsoluteDate getStop() {
return attitudeDataLines.get(attitudeDataLines.size() - 1).getDate();
}
/** {@inheritDoc} */
@Override
public String getInterpolationMethod() {
return interpolationMethod;
}
/** {@inheritDoc} */
@Override
public int getInterpolationSamples() {
return interpolationSamples;
}
/** {@inheritDoc} */
@Override
public AngularDerivativesFilter getAvailableDerivatives() {
return availableDerivatives;
}
/** {@inheritDoc} */
@Override
public BoundedAttitudeProvider getAttitudeProvider() {
return new TabulatedProvider(getAngularCoordinates(),
getInterpolationSamples(), getAvailableDerivatives(),
getStart(), getStop(),
new FixedFrameBuilder(getReferenceFrame()));
}
}
}