OEMFile.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.ccsds;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import org.hipparchus.linear.RealMatrix;
import org.orekit.errors.OrekitException;
import org.orekit.errors.OrekitMessages;
import org.orekit.files.general.EphemerisFile;
import org.orekit.frames.Frame;
import org.orekit.frames.LOFType;
import org.orekit.time.AbsoluteDate;
import org.orekit.time.TimeScale;
import org.orekit.utils.CartesianDerivativesFilter;
import org.orekit.utils.TimeStampedPVCoordinates;
/** This class stocks all the information of the OEM File parsed by OEMParser. It
* contains the header and a list of Ephemerides Blocks each containing
* metadata, a list of ephemerides data lines and optional covariance matrices
* (and their metadata).
* @author sports
* @author Evan Ward
* @since 6.1
*/
public class OEMFile extends ODMFile implements EphemerisFile {
/** List of ephemeris blocks. */
private List<EphemeridesBlock> ephemeridesBlocks;
/** OEMFile constructor. */
public OEMFile() {
ephemeridesBlocks = new ArrayList<EphemeridesBlock>();
}
/** Add a block to the list of ephemeris blocks. */
void addEphemeridesBlock() {
ephemeridesBlocks.add(new EphemeridesBlock());
}
/**Get the list of ephemerides blocks as an unmodifiable list.
* @return the list of ephemerides blocks
*/
public List<EphemeridesBlock> getEphemeridesBlocks() {
return Collections.unmodifiableList(ephemeridesBlocks);
}
/** Check that, according to the CCSDS standard, every OEMBlock has the same time system.
*/
void checkTimeSystems() {
final CcsdsTimeScale timeSystem = getEphemeridesBlocks().get(0).getMetaData().getTimeSystem();
for (final EphemeridesBlock block : ephemeridesBlocks) {
if (!timeSystem.equals(block.getMetaData().getTimeSystem())) {
throw new OrekitException(OrekitMessages.CCSDS_OEM_INCONSISTENT_TIME_SYSTEMS,
timeSystem, block.getMetaData().getTimeSystem());
}
}
}
@Override
public Map<String, OemSatelliteEphemeris> getSatellites() {
final Map<String, List<EphemeridesBlock>> satellites = new HashMap<>();
for (final EphemeridesBlock ephemeridesBlock : ephemeridesBlocks) {
final String id = ephemeridesBlock.getMetaData().getObjectID();
satellites.putIfAbsent(id, new ArrayList<>());
satellites.get(id).add(ephemeridesBlock);
}
final Map<String, OemSatelliteEphemeris> ret = new HashMap<>();
for (final Entry<String, List<EphemeridesBlock>> entry : satellites.entrySet()) {
final String id = entry.getKey();
ret.put(id, new OemSatelliteEphemeris(id, getMuUsed(), entry.getValue()));
}
return ret;
}
/** The Ephemerides Blocks class contain metadata, the list of ephemerides data
* lines and optional covariance matrices (and their metadata). The reason
* for which the ephemerides have been separated into blocks is that the
* ephemerides of two different blocks are not suited for interpolation.
* @author sports
*/
public class EphemeridesBlock implements EphemerisSegment {
/** Meta-data for the block. */
private ODMMetaData metaData;
/** Start of total time span covered by ephemerides data and covariance
* data. */
private AbsoluteDate startTime;
/** End of total time span covered by ephemerides data and covariance
* data. */
private AbsoluteDate stopTime;
/** Start of useable time span covered by ephemerides data, it may be
* necessary to allow for proper interpolation. */
private AbsoluteDate useableStartTime;
/** End of useable time span covered by ephemerides data, it may be
* necessary to allow for proper interpolation. */
private AbsoluteDate useableStopTime;
/** The interpolation method to be used. */
private String interpolationMethod;
/** The interpolation degree. */
private int interpolationDegree;
/** List of ephemerides data lines. */
private List<TimeStampedPVCoordinates> ephemeridesDataLines;
/** True iff all data points in this block have accelleration data. */
private boolean hasAcceleration;
/** List of covariance matrices. */
private List<CovarianceMatrix> covarianceMatrices;
/** Tests whether the reference frame has an epoch associated to it. */
private boolean hasRefFrameEpoch;
/** Ephemerides Data Lines comments. The list contains a string for each
* line of comment. */
private List<String> ephemeridesDataLinesComment;
/** EphemeridesBlock constructor. */
public EphemeridesBlock() {
metaData = new ODMMetaData(OEMFile.this);
ephemeridesDataLines = new ArrayList<>();
covarianceMatrices = new ArrayList<CovarianceMatrix>();
hasAcceleration = true;
}
/** Get the list of Ephemerides data lines.
* @return a reference to the internal list of Ephemerides data lines
*/
List<TimeStampedPVCoordinates> getEphemeridesDataLines() {
return this.ephemeridesDataLines;
}
@Override
public CartesianDerivativesFilter getAvailableDerivatives() {
return hasAcceleration ? CartesianDerivativesFilter.USE_PVA :
CartesianDerivativesFilter.USE_PV;
}
/**
* Update the value of {@link #hasAcceleration}.
*
* @param pointHasAcceleration true iff the current data point has acceleration
* data.
*/
void updateHasAcceleration(final boolean pointHasAcceleration) {
this.hasAcceleration = this.hasAcceleration && pointHasAcceleration;
}
@Override
public List<TimeStampedPVCoordinates> getCoordinates() {
return Collections.unmodifiableList(this.ephemeridesDataLines);
}
/** Get the list of Covariance Matrices.
* @return the list of Covariance Matrices
*/
public List<CovarianceMatrix> getCovarianceMatrices() {
return covarianceMatrices;
}
/** Get the meta-data for the block.
* @return meta-data for the block
*/
public ODMMetaData getMetaData() {
return metaData;
}
@Override
public double getMu() {
return getMuUsed();
}
@Override
public String getFrameCenterString() {
return this.getMetaData().getCenterName();
}
@Override
public String getFrameString() {
return this.getMetaData().getFrameString();
}
@Override
public Frame getFrame() {
return this.getMetaData().getFrame();
}
@Override
public Frame getInertialFrame() {
final Frame frame = getFrame();
if (frame.isPseudoInertial()) {
return frame;
}
return metaData.getODMFile().getDataContext().getFrames().getGCRF();
}
@Override
public String getTimeScaleString() {
return this.getMetaData().getTimeSystem().toString();
}
@Override
public TimeScale getTimeScale() {
return this.getMetaData().getTimeScale();
}
/** Get start of total time span covered by ephemerides data and
* covariance data.
* @return the start time
*/
public AbsoluteDate getStartTime() {
return startTime;
}
/** Set start of total time span covered by ephemerides data and
* covariance data.
* @param startTime the time to be set
*/
void setStartTime(final AbsoluteDate startTime) {
this.startTime = startTime;
}
/** Get end of total time span covered by ephemerides data and covariance
* data.
* @return the stop time
*/
public AbsoluteDate getStopTime() {
return stopTime;
}
/** Set end of total time span covered by ephemerides data and covariance
* data.
* @param stopTime the time to be set
*/
void setStopTime(final AbsoluteDate stopTime) {
this.stopTime = stopTime;
}
/** Get start of useable time span covered by ephemerides data, it may be
* necessary to allow for proper interpolation.
* @return the useable start time
*/
public AbsoluteDate getUseableStartTime() {
return useableStartTime;
}
/** Set start of useable time span covered by ephemerides data, it may be
* necessary to allow for proper interpolation.
* @param useableStartTime the time to be set
*/
void setUseableStartTime(final AbsoluteDate useableStartTime) {
this.useableStartTime = useableStartTime;
}
/** Get end of useable time span covered by ephemerides data, it may be
* necessary to allow for proper interpolation.
* @return the useable stop time
*/
public AbsoluteDate getUseableStopTime() {
return useableStopTime;
}
/** Set end of useable time span covered by ephemerides data, it may be
* necessary to allow for proper interpolation.
* @param useableStopTime the time to be set
*/
void setUseableStopTime(final AbsoluteDate useableStopTime) {
this.useableStopTime = useableStopTime;
}
@Override
public AbsoluteDate getStart() {
// usable start time overrides start time if it is set
final AbsoluteDate start = this.getUseableStartTime();
if (start != null) {
return start;
} else {
return this.getStartTime();
}
}
@Override
public AbsoluteDate getStop() {
// useable stop time overrides stop time if it is set
final AbsoluteDate stop = this.getUseableStopTime();
if (stop != null) {
return stop;
} else {
return this.getStopTime();
}
}
/** Get the interpolation method to be used.
* @return the interpolation method
*/
public String getInterpolationMethod() {
return interpolationMethod;
}
/** Set the interpolation method to be used.
* @param interpolationMethod the interpolation method to be set
*/
void setInterpolationMethod(final String interpolationMethod) {
this.interpolationMethod = interpolationMethod;
}
/** Get the interpolation degree.
* @return the interpolation degree
*/
public int getInterpolationDegree() {
return interpolationDegree;
}
/** Set the interpolation degree.
* @param interpolationDegree the interpolation degree to be set
*/
void setInterpolationDegree(final int interpolationDegree) {
this.interpolationDegree = interpolationDegree;
}
@Override
public int getInterpolationSamples() {
// From the standard it is not entirely clear how to interpret the degree.
return getInterpolationDegree() + 1;
}
/** Get boolean testing whether the reference frame has an epoch associated to it.
* @return true if the reference frame has an epoch associated to it
* false otherwise
*/
public boolean getHasRefFrameEpoch() {
return hasRefFrameEpoch;
}
/** Set boolean testing whether the reference frame has an epoch associated to it.
* @param hasRefFrameEpoch the boolean to be set.
*/
void setHasRefFrameEpoch(final boolean hasRefFrameEpoch) {
this.hasRefFrameEpoch = hasRefFrameEpoch;
}
/** Get the ephemerides data lines comment.
* @return the comment
*/
public List<String> getEphemeridesDataLinesComment() {
return ephemeridesDataLinesComment;
}
/** Set the ephemerides data lines comment.
* @param ephemeridesDataLinesComment the comment to be set
*/
void setEphemeridesDataLinesComment(final List<String> ephemeridesDataLinesComment) {
this.ephemeridesDataLinesComment = new ArrayList<String>(ephemeridesDataLinesComment);
}
}
/** The CovarianceMatrix class represents a covariance matrix and its
* metadata: epoch and frame.
* @author sports
*/
public static class CovarianceMatrix {
/** Covariance matrix. */
private RealMatrix matrix;
/** Epoch relative to the covariance matrix. */
private AbsoluteDate epoch;
/** Coordinate system for covariance matrix, for Local Orbital Frames. */
private LOFType lofType;
/** Coordinate system for covariance matrix, for absolute frames.
* If not given it is set equal to refFrame. */
private Frame frame;
/** Covariance Matrix constructor.
* @param epoch the epoch
* @param lofType coordinate system for covariance matrix, for Local Orbital Frames
* @param frame coordinate system for covariance matrix, for absolute frames
* @param lastMatrix the covariance matrix
*/
CovarianceMatrix(final AbsoluteDate epoch,
final LOFType lofType, final Frame frame,
final RealMatrix lastMatrix) {
this.matrix = lastMatrix;
this.epoch = epoch;
this.lofType = lofType;
this.frame = frame;
}
/** Get the covariance matrix.
* @return the covariance matrix
*/
public RealMatrix getMatrix() {
return matrix;
}
/** Get the epoch relative to the covariance matrix.
* @return the epoch
*/
public AbsoluteDate getEpoch() {
return epoch;
}
/** Get coordinate system for covariance matrix, for Local Orbital Frames.
* <p>
* The value returned is null if the covariance matrix is given in an
* absolute frame rather than a Local Orbital Frame. In this case, the
* method {@link #getFrame()} must be used instead.
* </p>
* @return the coordinate system for covariance matrix, or null if the
* covariance matrix is given in an absolute frame rather than a Local
* Orbital Frame
*/
public LOFType getLofType() {
return lofType;
}
/** Get coordinate system for covariance matrix, for absolute frames.
* <p>
* The value returned is null if the covariance matrix is given in a
* Local Orbital Frame rather than an absolute frame. In this case, the
* method {@link #getLofType()} must be used instead.
* </p>
* @return the coordinate system for covariance matrix
*/
public Frame getFrame() {
return frame;
}
}
/** OEM ephemeris blocks for a single satellite. */
public static class OemSatelliteEphemeris implements SatelliteEphemeris {
/** ID of the satellite. */
private final String id;
/** Gravitational prameter for the satellite, in m^3 / s^2. */
private final double mu;
/** The ephemeris data for the satellite. */
private final List<EphemeridesBlock> blocks;
/**
* Create a container for the set of ephemeris blocks in the file that pertain to
* a single satellite.
*
* @param id of the satellite.
* @param mu standard gravitational parameter used to create orbits for the
* satellite, in m^3 / s^2.
* @param blocks containing ephemeris data for the satellite.
*/
OemSatelliteEphemeris(final String id,
final double mu,
final List<EphemeridesBlock> blocks) {
this.id = id;
this.mu = mu;
this.blocks = blocks;
}
@Override
public String getId() {
return this.id;
}
@Override
public double getMu() {
return this.mu;
}
@Override
public List<EphemeridesBlock> getSegments() {
return Collections.unmodifiableList(blocks);
}
@Override
public AbsoluteDate getStart() {
return blocks.get(0).getStart();
}
@Override
public AbsoluteDate getStop() {
return blocks.get(blocks.size() - 1).getStop();
}
}
}