Java tutorial
/* Copyright 2002-2015 CS Systmes d'Information * Licensed to CS Systmes d'Information (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.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.List; import java.util.Scanner; import org.apache.commons.math3.exception.util.DummyLocalizable; import org.apache.commons.math3.geometry.euclidean.threed.Vector3D; import org.apache.commons.math3.linear.MatrixUtils; import org.apache.commons.math3.linear.RealMatrix; import org.orekit.errors.OrekitException; import org.orekit.errors.OrekitMessages; import org.orekit.files.general.OrbitFileParser; import org.orekit.frames.Frame; import org.orekit.frames.LOFType; import org.orekit.orbits.CartesianOrbit; import org.orekit.time.AbsoluteDate; import org.orekit.utils.IERSConventions; import org.orekit.utils.PVCoordinates; /** * A parser for the CCSDS OEM (Orbit Ephemeris Message). * @author sports * @since 6.1 */ public class OEMParser extends ODMParser implements OrbitFileParser { /** Simple constructor. * <p> * This class is immutable, and hence thread safe. When parts * must be changed, such as reference date for Mission Elapsed Time or * Mission Relative Time time systems, or the gravitational coefficient or * the IERS conventions, the various {@code withXxx} methods must be called, * which create a new immutable instance with the new parameters. This * is a combination of the <a href="">builder design pattern</a> and * a <a href="http://en.wikipedia.org/wiki/Fluent_interface">fluent * interface</a>. * </p> * <p> * The initial date for Mission Elapsed Time and Mission Relative Time time systems is not set here. * If such time systems are used, it must be initialized before parsing by calling {@link * #withMissionReferenceDate(AbsoluteDate)}. * </p> * <p> * The gravitational coefficient is not set here. If it is needed in order * to parse Cartesian orbits where the value is not set in the CCSDS file, it must * be initialized before parsing by calling {@link #withMu(double)}. * </p> * <p> * The IERS conventions to use is not set here. If it is needed in order to * parse some reference frames or UT1 time scale, it must be initialized before * parsing by calling {@link #withConventions(IERSConventions)}. * </p> */ public OEMParser() { this(AbsoluteDate.FUTURE_INFINITY, Double.NaN, null, true, 0, 0, ""); } /** Complete constructor. * @param missionReferenceDate reference date for Mission Elapsed Time or Mission Relative Time time systems * @param mu gravitational coefficient * @param conventions IERS Conventions * @param simpleEOP if true, tidal effects are ignored when interpolating EOP * @param launchYear launch year for TLEs * @param launchNumber launch number for TLEs * @param launchPiece piece of launch (from "A" to "ZZZ") for TLEs */ private OEMParser(final AbsoluteDate missionReferenceDate, final double mu, final IERSConventions conventions, final boolean simpleEOP, final int launchYear, final int launchNumber, final String launchPiece) { super(missionReferenceDate, mu, conventions, simpleEOP, launchYear, launchNumber, launchPiece); } /** {@inheritDoc} */ public OEMParser withMissionReferenceDate(final AbsoluteDate newMissionReferenceDate) { return new OEMParser(newMissionReferenceDate, getMu(), getConventions(), isSimpleEOP(), getLaunchYear(), getLaunchNumber(), getLaunchPiece()); } /** {@inheritDoc} */ public OEMParser withMu(final double newMu) { return new OEMParser(getMissionReferenceDate(), newMu, getConventions(), isSimpleEOP(), getLaunchYear(), getLaunchNumber(), getLaunchPiece()); } /** {@inheritDoc} */ public OEMParser withConventions(final IERSConventions newConventions) { return new OEMParser(getMissionReferenceDate(), getMu(), newConventions, isSimpleEOP(), getLaunchYear(), getLaunchNumber(), getLaunchPiece()); } /** {@inheritDoc} */ public OEMParser withSimpleEOP(final boolean newSimpleEOP) { return new OEMParser(getMissionReferenceDate(), getMu(), getConventions(), newSimpleEOP, getLaunchYear(), getLaunchNumber(), getLaunchPiece()); } /** {@inheritDoc} */ public OEMParser withInternationalDesignator(final int newLaunchYear, final int newLaunchNumber, final String newLaunchPiece) { return new OEMParser(getMissionReferenceDate(), getMu(), getConventions(), isSimpleEOP(), newLaunchYear, newLaunchNumber, newLaunchPiece); } /** {@inheritDoc} */ @Override public OEMFile parse(final String fileName) throws OrekitException { return (OEMFile) super.parse(fileName); } /** {@inheritDoc} */ public OEMFile parse(final InputStream stream, final String fileName) throws OrekitException { try { final BufferedReader reader = new BufferedReader(new InputStreamReader(stream, "UTF-8")); // initialize internal data structures final ParseInfo pi = new ParseInfo(); pi.fileName = fileName; final OEMFile file = pi.file; // set the additional data that has been configured prior the parsing by the user. pi.file.setMissionReferenceDate(getMissionReferenceDate()); pi.file.setMuSet(getMu()); pi.file.setConventions(getConventions()); for (String line = reader.readLine(); line != null; line = reader.readLine()) { ++pi.lineNumber; if (line.trim().length() == 0) { continue; } pi.keyValue = new KeyValue(line, pi.lineNumber, pi.fileName); if (pi.keyValue.getKeyword() == null) { throw new OrekitException(OrekitMessages.CCSDS_UNEXPECTED_KEYWORD, pi.lineNumber, pi.fileName, line); } switch (pi.keyValue.getKeyword()) { case CCSDS_OEM_VERS: file.setFormatVersion(pi.keyValue.getDoubleValue()); break; case META_START: file.addEphemeridesBlock(); pi.lastEphemeridesBlock = file.getEphemeridesBlocks() .get(file.getEphemeridesBlocks().size() - 1); pi.lastEphemeridesBlock.getMetaData().setLaunchYear(getLaunchYear()); pi.lastEphemeridesBlock.getMetaData().setLaunchNumber(getLaunchNumber()); pi.lastEphemeridesBlock.getMetaData().setLaunchPiece(getLaunchPiece()); break; case START_TIME: pi.lastEphemeridesBlock.setStartTime(parseDate(pi.keyValue.getValue(), pi.lastEphemeridesBlock.getMetaData().getTimeSystem())); break; case USEABLE_START_TIME: pi.lastEphemeridesBlock.setUseableStartTime(parseDate(pi.keyValue.getValue(), pi.lastEphemeridesBlock.getMetaData().getTimeSystem())); break; case USEABLE_STOP_TIME: pi.lastEphemeridesBlock.setUseableStopTime(parseDate(pi.keyValue.getValue(), pi.lastEphemeridesBlock.getMetaData().getTimeSystem())); break; case STOP_TIME: pi.lastEphemeridesBlock.setStopTime(parseDate(pi.keyValue.getValue(), pi.lastEphemeridesBlock.getMetaData().getTimeSystem())); break; case INTERPOLATION: pi.lastEphemeridesBlock.setInterpolationMethod(pi.keyValue.getValue()); break; case INTERPOLATION_DEGREE: pi.lastEphemeridesBlock.setInterpolationDegree(Integer.parseInt(pi.keyValue.getValue())); break; case META_STOP: file.setMuUsed(); parseEphemeridesDataLines(reader, pi); break; case COVARIANCE_START: parseCovarianceDataLines(reader, pi); break; default: boolean parsed = false; parsed = parsed || parseComment(pi.keyValue, pi.commentTmp); parsed = parsed || parseHeaderEntry(pi.keyValue, file, pi.commentTmp); if (pi.lastEphemeridesBlock != null) { parsed = parsed || parseMetaDataEntry(pi.keyValue, pi.lastEphemeridesBlock.getMetaData(), pi.commentTmp); } if (!parsed) { throw new OrekitException(OrekitMessages.CCSDS_UNEXPECTED_KEYWORD, pi.lineNumber, pi.fileName, line); } } } file.checkTimeSystems(); return file; } catch (IOException ioe) { throw new OrekitException(ioe, new DummyLocalizable(ioe.getMessage())); } } /** * Parse an ephemeris data line and add its content to the ephemerides * block. * * @param reader the reader * @param pi the parser info * @exception IOException if an error occurs while reading from the stream * @exception OrekitException if a date cannot be parsed */ private void parseEphemeridesDataLines(final BufferedReader reader, final ParseInfo pi) throws OrekitException, IOException { for (String line = reader.readLine(); line != null; line = reader.readLine()) { ++pi.lineNumber; if (line.trim().length() > 0) { pi.keyValue = new KeyValue(line, pi.lineNumber, pi.fileName); if (pi.keyValue.getKeyword() == null) { Scanner sc = null; try { sc = new Scanner(line); final AbsoluteDate date = parseDate(sc.next(), pi.lastEphemeridesBlock.getMetaData().getTimeSystem()); final Vector3D position = new Vector3D(Double.parseDouble(sc.next()) * 1000, Double.parseDouble(sc.next()) * 1000, Double.parseDouble(sc.next()) * 1000); final Vector3D velocity = new Vector3D(Double.parseDouble(sc.next()) * 1000, Double.parseDouble(sc.next()) * 1000, Double.parseDouble(sc.next()) * 1000); final CartesianOrbit orbit = new CartesianOrbit(new PVCoordinates(position, velocity), pi.lastEphemeridesBlock.getMetaData().getFrame(), date, pi.file.getMuUsed()); Vector3D acceleration = null; if (sc.hasNext()) { acceleration = new Vector3D(Double.parseDouble(sc.next()) * 1000, Double.parseDouble(sc.next()) * 1000, Double.parseDouble(sc.next()) * 1000); } final OEMFile.EphemeridesDataLine epDataLine = new OEMFile.EphemeridesDataLine(orbit, acceleration); pi.lastEphemeridesBlock.getEphemeridesDataLines().add(epDataLine); } catch (NumberFormatException nfe) { throw new OrekitException(OrekitMessages.UNABLE_TO_PARSE_LINE_IN_FILE, pi.lineNumber, pi.fileName, line); } finally { if (sc != null) { sc.close(); } } } else { switch (pi.keyValue.getKeyword()) { case META_START: pi.lastEphemeridesBlock.setEphemeridesDataLinesComment(pi.commentTmp); pi.commentTmp.clear(); pi.lineNumber--; reader.reset(); return; case COVARIANCE_START: pi.lastEphemeridesBlock.setEphemeridesDataLinesComment(pi.commentTmp); pi.commentTmp.clear(); pi.lineNumber--; reader.reset(); return; case COMMENT: pi.commentTmp.add(pi.keyValue.getValue()); break; default: throw new OrekitException(OrekitMessages.CCSDS_UNEXPECTED_KEYWORD, pi.lineNumber, pi.fileName, line); } } } reader.mark(300); } } /** * Parse the covariance data lines, create a set of CovarianceMatrix objects * and add them in the covarianceMatrices list of the ephemerides block. * * @param reader the reader * @param pi the parser info * @throws IOException if an error occurs while reading from the stream * @throws OrekitException if the frame cannot be retrieved */ private void parseCovarianceDataLines(final BufferedReader reader, final ParseInfo pi) throws IOException, OrekitException { int i = 0; for (String line = reader.readLine(); line != null; line = reader.readLine()) { ++pi.lineNumber; if (line.trim().length() == 0) { continue; } pi.keyValue = new KeyValue(line, pi.lineNumber, pi.fileName); if (pi.keyValue.getKeyword() == null) { final Scanner sc = new Scanner(line); for (int j = 0; j < i + 1; j++) { try { pi.lastMatrix.addToEntry(i, j, Double.parseDouble(sc.next())); } catch (NumberFormatException nfe) { sc.close(); throw new OrekitException(OrekitMessages.UNABLE_TO_PARSE_LINE_IN_FILE, pi.lineNumber, pi.fileName, line); } if (j != i) { pi.lastMatrix.addToEntry(j, i, pi.lastMatrix.getEntry(i, j)); } } if (i == 5) { final OEMFile.CovarianceMatrix cm = new OEMFile.CovarianceMatrix(pi.epoch, pi.covRefLofType, pi.covRefFrame, pi.lastMatrix); pi.lastEphemeridesBlock.getCovarianceMatrices().add(cm); } i++; if (sc != null) { sc.close(); } } else { switch (pi.keyValue.getKeyword()) { case EPOCH: i = 0; pi.covRefLofType = null; pi.covRefFrame = null; pi.lastMatrix = MatrixUtils.createRealMatrix(6, 6); pi.epoch = parseDate(pi.keyValue.getValue(), pi.lastEphemeridesBlock.getMetaData().getTimeSystem()); break; case COV_REF_FRAME: final CCSDSFrame frame = parseCCSDSFrame(pi.keyValue.getValue()); if (frame.isLof()) { pi.covRefLofType = frame.getLofType(); pi.covRefFrame = null; } else { pi.covRefLofType = null; pi.covRefFrame = frame.getFrame(getConventions(), isSimpleEOP()); } break; case COVARIANCE_STOP: return; default: throw new OrekitException(OrekitMessages.CCSDS_UNEXPECTED_KEYWORD, pi.lineNumber, pi.fileName, line); } } } } /** Private class used to stock OEM parsing info. * @author sports */ private static class ParseInfo { /** Ephemerides block being parsed. */ private OEMFile.EphemeridesBlock lastEphemeridesBlock; /** Name of the file. */ private String fileName; /** Current line number. */ private int lineNumber; /** OEM file being read. */ private OEMFile file; /** Key value of the line being read. */ private KeyValue keyValue; /** Stored epoch. */ private AbsoluteDate epoch; /** Covariance reference type of Local Orbital Frame. */ private LOFType covRefLofType; /** Covariance reference frame. */ private Frame covRefFrame; /** Stored matrix. */ private RealMatrix lastMatrix; /** Stored comments. */ private List<String> commentTmp; /** Create a new {@link ParseInfo} object. */ protected ParseInfo() { lineNumber = 0; file = new OEMFile(); commentTmp = new ArrayList<String>(); } } }