EopC04FilesLoader.java
/* Copyright 2002-2024 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.frames;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.SortedSet;
import java.util.function.Supplier;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.orekit.data.DataProvidersManager;
import org.orekit.errors.OrekitException;
import org.orekit.errors.OrekitMessages;
import org.orekit.time.AbsoluteDate;
import org.orekit.time.DateComponents;
import org.orekit.time.TimeComponents;
import org.orekit.time.TimeScale;
import org.orekit.utils.Constants;
import org.orekit.utils.IERSConventions;
import org.orekit.utils.IERSConventions.NutationCorrectionConverter;
/** Loader for EOP C04 files.
* <p>EOP C04 files contain {@link EOPEntry
* Earth Orientation Parameters} consistent with ITRF20xx for one year periods, with various
* xx (05, 08, 14, 20) depending on the data source.</p>
* <p>The EOP C04 files retrieved from the old ftp site
* <a href="ftp://ftp.iers.org/products/eop/long-term/">ftp://ftp.iers.org/products/eop/long-term/</a>
* were recognized thanks to their base names, which must match one of the patterns
* {@code eopc04_##_IAU2000.##} or {@code eopc04_##.##} (or the same ending with <code>.gz</code> for
* gzip-compressed files) where # stands for a digit character. As of early 2023, this ftp site
* seems not to be accessible anymore.</p>
* <p>
* The official source for these files is now the web site
* <a href="https://hpiers.obspm.fr/eoppc/eop/">https://hpiers.obspm.fr/eoppc/eop/</a>. These
* files do <em>not</em> follow the old naming convention that was used in the older ftp site.
* They lack the _05, _08 or _14 markers in the file names. The ITRF year appears only in the URL
* (with directories eopc04_05, eop04_c08…). The directory for the current data is named eopc04
* without any suffix. So before 2023-02-14 the eopc04 directory would contain files compatible with
* ITRF2014 and after 2023-02-14 it would contain files compatible with ITRF2020. In each directory,
* the files don't have any marker, hence users downloading eopc04.99 file from eopc04_05 would get
* a file compatible with ITRF2005 whereas users downloading a file with the exact same name eopc04.99
* but from eop04_c08 would get a file compatible with ITRF2008.
* </p>
* <p>
* Starting with Orekit version 12.0, the ITRF year is retrieved by analyzing the file header, it is
* not linked to file name anymore, hence it is compatible with any IERS site layout.
* </p>
* <p>
* This class is immutable and hence thread-safe
* </p>
* @author Luc Maisonobe
*/
class EopC04FilesLoader extends AbstractEopLoader implements EopHistoryLoader {
/** Build a loader for IERS EOP C04 files.
* @param supportedNames regular expression for supported files names
* @param manager provides access to the EOP C04 files.
* @param utcSupplier UTC time scale.
*/
EopC04FilesLoader(final String supportedNames,
final DataProvidersManager manager,
final Supplier<TimeScale> utcSupplier) {
super(supportedNames, manager, utcSupplier);
}
/** {@inheritDoc} */
public void fillHistory(final IERSConventions.NutationCorrectionConverter converter,
final SortedSet<EOPEntry> history) {
final Parser parser = new Parser(converter, getUtc());
final EopParserLoader loader = new EopParserLoader(parser);
this.feed(loader);
history.addAll(loader.getEop());
}
/** Internal class performing the parsing. */
static class Parser extends AbstractEopParser {
/** Simple constructor.
* @param converter converter to use
* @param utc time scale for parsing dates.
*/
Parser(final NutationCorrectionConverter converter,
final TimeScale utc) {
super(converter, null, utc);
}
/** {@inheritDoc} */
public Collection<EOPEntry> parse(final InputStream input, final String name)
throws IOException, OrekitException {
final List<EOPEntry> history = new ArrayList<>();
// set up a reader for line-oriented EOP C04 files
try (BufferedReader reader = new BufferedReader(new InputStreamReader(input, StandardCharsets.UTF_8))) {
// reset parse info to start new file (do not clear history!)
int lineNumber = 0;
boolean inHeader = true;
final LineParser[] tentativeParsers = new LineParser[] {
new LineWithoutRatesParser(name),
new LineWithRatesParser(name)
};
LineParser selectedParser = null;
// read all file
for (String line = reader.readLine(); line != null; line = reader.readLine()) {
++lineNumber;
boolean parsed = false;
if (inHeader) {
// maybe it's an header line
for (final LineParser parser : tentativeParsers) {
if (parser.parseHeaderLine(line)) {
// we recognized one EOP C04 format
selectedParser = parser;
break;
}
}
}
if (selectedParser != null) {
// maybe it's a data line
final EOPEntry entry = selectedParser.parseDataLine(line);
if (entry != null) {
// this is a data line, build an entry from the extracted fields
history.add(entry);
parsed = true;
// we know we have already finished header
inHeader = false;
}
}
if (!(inHeader || parsed)) {
throw new OrekitException(OrekitMessages.UNABLE_TO_PARSE_LINE_IN_FILE,
lineNumber, name, line);
}
}
// check if we have read something
if (inHeader) {
throw new OrekitException(OrekitMessages.NOT_A_SUPPORTED_IERS_DATA_FILE, name);
}
}
return history;
}
/** Base parser for EOP C04 lines.
* @since 12.0
*/
private abstract class LineParser {
/** Pattern for ITRF version. */
private final Pattern itrfVersionPattern;
/** Pattern for columns header. */
private final Pattern columnHeaderPattern;
/** Pattern for data lines. */
private final Pattern dataPattern;
/** Year group. */
private final int yearGroup;
/** Month group. */
private final int monthGroup;
/** Day group. */
private final int dayGroup;
/** MJD group. */
private final int mjdGroup;
/** Name of the stream for error messages. */
private final String name;
/** ITRF version. */
private ITRFVersion itrfVersion;
/** Simple constructor.
* @param itrfVersionRegexp regular expression for ITRF version
* @param columnsHeaderRegexp regular expression for columns header
* @param dataRegexp regular expression for data lines
* @param yearGroup year group
* @param monthGroup month group
* @param dayGroup day group
* @param mjdGroup MJD group
* @param name of the stream for error messages.
*/
protected LineParser(final String itrfVersionRegexp, final String columnsHeaderRegexp,
final String dataRegexp,
final int yearGroup, final int monthGroup, final int dayGroup,
final int mjdGroup, final String name) {
this.itrfVersionPattern = Pattern.compile(itrfVersionRegexp);
this.columnHeaderPattern = Pattern.compile(columnsHeaderRegexp);
this.dataPattern = Pattern.compile(dataRegexp);
this.yearGroup = yearGroup;
this.monthGroup = monthGroup;
this.dayGroup = dayGroup;
this.mjdGroup = mjdGroup;
this.name = name;
}
/** Get the ITRF version for this EOP C04 file.
* @return ITRF version
*/
protected ITRFVersion getItrfVersion() {
return itrfVersion;
}
/** Parse a header line.
* @param line line to parse
* @return true if line was recognized (either ITRF version or columns header)
*/
public boolean parseHeaderLine(final String line) {
final Matcher itrfVersionMatcher = itrfVersionPattern.matcher(line);
if (itrfVersionMatcher.matches()) {
switch (Integer.parseInt(itrfVersionMatcher.group(1))) {
case 5 :
itrfVersion = ITRFVersion.ITRF_2005;
break;
case 8 :
itrfVersion = ITRFVersion.ITRF_2008;
break;
case 14 :
itrfVersion = ITRFVersion.ITRF_2014;
break;
case 20 :
itrfVersion = ITRFVersion.ITRF_2020;
break;
default :
throw new OrekitException(OrekitMessages.NO_SUCH_ITRF_FRAME, itrfVersionMatcher.group(1));
}
return true;
} else {
final Matcher columnHeaderMatcher = columnHeaderPattern.matcher(line);
if (columnHeaderMatcher.matches()) {
parseColumnsHeaderLine(columnHeaderMatcher);
return true;
}
return false;
}
}
/** Parse a data line.
* @param line line to parse
* @return EOP entry for the line, or null if line does not match expected regular expression
*/
public EOPEntry parseDataLine(final String line) {
final Matcher matcher = dataPattern.matcher(line);
if (!matcher.matches()) {
// this is not a data line
return null;
}
// check date
final DateComponents dc = new DateComponents(Integer.parseInt(matcher.group(yearGroup)),
Integer.parseInt(matcher.group(monthGroup)),
Integer.parseInt(matcher.group(dayGroup)));
final int mjd = Integer.parseInt(matcher.group(mjdGroup));
if (dc.getMJD() != mjd) {
throw new OrekitException(OrekitMessages.INCONSISTENT_DATES_IN_IERS_FILE,
name, dc.getYear(), dc.getMonth(), dc.getDay(), mjd);
}
return parseDataLine(matcher, dc);
}
/** Parse a columns header line.
* @param matcher matcher for line
*/
protected abstract void parseColumnsHeaderLine(Matcher matcher);
/** Parse a data line.
* @param matcher matcher for line
* @param dc date components already extracted from the line
* @return EOP entry for the line
*/
protected abstract EOPEntry parseDataLine(Matcher matcher, DateComponents dc);
}
/** Parser for data lines without pole rates.
* <p>
* ITRF markers have either the following form:
* </p>
* <pre>
* EOP (IERS) 05 C04
* </pre>
* <p>
* or the following form:
* </p>
* <pre>
* EOP (IERS) 14 C04 TIME SERIES
* </pre>
* <p>
* Header have either the following form:
* </p>
* <pre>
* Date MJD x y UT1-UTC LOD dPsi dEps x Err y Err UT1-UTC Err LOD Err dPsi Err dEpsilon Err
* " " s s " " " " s s " "
* (0h UTC)
* </pre>
* <p>
* or the following form:
* </p>
* <pre>
* Date MJD x y UT1-UTC LOD dX dY x Err y Err UT1-UTC Err LOD Err dX Err dY Err
* " " s s " " " " s s " "
* (0h UTC)
* </pre>
* <p>
* The data lines in the EOP C04 yearly data files have either the following fixed form:
* </p>
* <pre>
* year month day MJD …12 floating values fields in decimal format...
* 2000 1 1 51544 0.043242 0.377915 0.3554777 …
* 2000 1 2 51545 0.043515 0.377753 0.3546065 …
* 2000 1 3 51546 0.043623 0.377452 0.3538444 …
* </pre>
* @since 12.0
*/
private class LineWithoutRatesParser extends LineParser {
/** Nutation header group. */
private static final int NUTATION_HEADER_GROUP = 1;
/** Year group. */
private static final int YEAR_GROUP = 1;
/** Month group. */
private static final int MONTH_GROUP = 2;
/** Day group. */
private static final int DAY_GROUP = 3;
/** MJD group. */
private static final int MJD_GROUP = 4;
/** X component of pole motion group. */
private static final int POLE_X_GROUP = 5;
/** Y component of pole motion group. */
private static final int POLE_Y_GROUP = 6;
/** UT1-UTC group. */
private static final int UT1_UTC_GROUP = 7;
/** LoD group. */
private static final int LOD_GROUP = 8;
/** Correction for nutation first field (either dX or dPsi). */
private static final int NUT_0_GROUP = 9;
/** Correction for nutation second field (either dY or dEps). */
private static final int NUT_1_GROUP = 10;
/** Indicator for non-rotating origin. */
private boolean isNonRotatingOrigin;
/** Simple constructor.
* @param name of the stream for error messages.
*/
LineWithoutRatesParser(final String name) {
super("^ +EOP +\\(IERS\\) +([0-9][0-9]) +C04.*",
"^ *Date +MJD +x +y +UT1-UTC +LOD +((?:dPsi +dEps)|(?:dX +dY)) .*",
"^(\\d+) +(\\d+) +(\\d+) +(\\d+) +(-?\\d+\\.\\d+) +(-?\\d+\\.\\d+) +(-?\\d+\\.\\d+) +(-?\\d+\\.\\d+) +(-?\\d+\\.\\d+) +(-?\\d+\\.\\d+)(?: +(-?\\d+\\.\\d+)){6}$",
YEAR_GROUP, MONTH_GROUP, DAY_GROUP, MJD_GROUP,
name);
}
/** {@inheritDoc} */
@Override
protected void parseColumnsHeaderLine(final Matcher matcher) {
isNonRotatingOrigin = matcher.group(NUTATION_HEADER_GROUP).startsWith("dX");
}
/** {@inheritDoc} */
@Override
protected EOPEntry parseDataLine(final Matcher matcher, final DateComponents dc) {
final AbsoluteDate date = new AbsoluteDate(dc, getUtc());
final double x = Double.parseDouble(matcher.group(POLE_X_GROUP)) * Constants.ARC_SECONDS_TO_RADIANS;
final double y = Double.parseDouble(matcher.group(POLE_Y_GROUP)) * Constants.ARC_SECONDS_TO_RADIANS;
final double dtu1 = Double.parseDouble(matcher.group(UT1_UTC_GROUP));
final double lod = Double.parseDouble(matcher.group(LOD_GROUP));
final double[] equinox;
final double[] nro;
if (isNonRotatingOrigin) {
nro = new double[] {
Double.parseDouble(matcher.group(NUT_0_GROUP)) * Constants.ARC_SECONDS_TO_RADIANS,
Double.parseDouble(matcher.group(NUT_1_GROUP)) * Constants.ARC_SECONDS_TO_RADIANS
};
equinox = getConverter().toEquinox(date, nro[0], nro[1]);
} else {
equinox = new double[] {
Double.parseDouble(matcher.group(NUT_0_GROUP)) * Constants.ARC_SECONDS_TO_RADIANS,
Double.parseDouble(matcher.group(NUT_1_GROUP)) * Constants.ARC_SECONDS_TO_RADIANS
};
nro = getConverter().toNonRotating(date, equinox[0], equinox[1]);
}
return new EOPEntry(dc.getMJD(), dtu1, lod, x, y, Double.NaN, Double.NaN,
equinox[0], equinox[1], nro[0], nro[1],
getItrfVersion(), date);
}
}
/** Parser for data lines with pole rates.
* <p>
* ITRF markers have either the following form:
* </p>
* <pre>
* # EOP (IERS) 20 C04 TIME SERIES consistent with ITRF 2020 - sampled at 0h UTC
* </pre>
* <p>
* Header have either the following form:
* </p>
* <pre>
* # YR MM DD HH MJD x(") y(") UT1-UTC(s) dX(") dY(") xrt(") yrt(") LOD(s) x Er y Er UT1-UTC Er dX Er dY Er xrt Er yrt Er LOD Er
* </pre>
* <p>
* The data lines in the EOP C04 yearly data files have either the following fixed form:
* </p>
* <pre>
* year month day hour MJD (in floating format) …16 floating values fields in decimal format...
* 2015 1 1 12 57023.50 0.030148 0.281014 …
* 2015 1 2 12 57024.50 0.029219 0.281441 …
* 2015 1 3 12 57025.50 0.028777 0.281824 …
* </pre>
* @since 12.0
*/
private class LineWithRatesParser extends LineParser {
/** Year group. */
private static final int YEAR_GROUP = 1;
/** Month group. */
private static final int MONTH_GROUP = 2;
/** Day group. */
private static final int DAY_GROUP = 3;
/** Hour group. */
private static final int HOUR_GROUP = 4;
/** MJD group. */
private static final int MJD_GROUP = 5;
/** X component of pole motion group. */
private static final int POLE_X_GROUP = 6;
/** Y component of pole motion group. */
private static final int POLE_Y_GROUP = 7;
/** UT1-UTC group. */
private static final int UT1_UTC_GROUP = 8;
/** Correction for nutation first field. */
private static final int NUT_DX_GROUP = 9;
/** Correction for nutation second field. */
private static final int NUT_DY_GROUP = 10;
/** X rate component of pole motion group.
* @since 12.0
*/
private static final int POLE_X_RATE_GROUP = 11;
/** Y rate component of pole motion group.
* @since 12.0
*/
private static final int POLE_Y_RATE_GROUP = 12;
/** LoD group. */
private static final int LOD_GROUP = 13;
/** Simple constructor.
* @param name of the stream for error messages.
*/
LineWithRatesParser(final String name) {
super("^# +EOP +\\(IERS\\) +([0-9][0-9]) +C04.*",
"^# +YR +MM +DD +H +MJD +x\\(\"\\) +y\\(\"\\) +UT1-UTC\\(s\\) +dX\\(\"\\) +dY\\(\"\\) +xrt\\(\"\\) +yrt\\'\"\\) +.*",
"^(\\d+) +(\\d+) +(\\d+) +(\\d+) +(\\d+)\\.\\d+ +(-?\\d+\\.\\d+) +(-?\\d+\\.\\d+) +(-?\\d+\\.\\d+) +(-?\\d+\\.\\d+) +(-?\\d+\\.\\d+) +(-?\\d+\\.\\d+) +(-?\\d+\\.\\d+) +(-?\\d+\\.\\d+)(?: +(-?\\d+\\.\\d+)){8}$", // we intentionally ignore MJD fractional part
YEAR_GROUP, MONTH_GROUP, DAY_GROUP, MJD_GROUP,
name);
}
/** {@inheritDoc} */
@Override
protected void parseColumnsHeaderLine(final Matcher matcher) {
// nothing to do here
}
/** {@inheritDoc} */
@Override
protected EOPEntry parseDataLine(final Matcher matcher, final DateComponents dc) {
final TimeComponents tc = new TimeComponents(Integer.parseInt(matcher.group(HOUR_GROUP)), 0, 0.0);
final AbsoluteDate date = new AbsoluteDate(dc, tc, getUtc());
final double x = Double.parseDouble(matcher.group(POLE_X_GROUP)) * Constants.ARC_SECONDS_TO_RADIANS;
final double y = Double.parseDouble(matcher.group(POLE_Y_GROUP)) * Constants.ARC_SECONDS_TO_RADIANS;
final double xRate = Double.parseDouble(matcher.group(POLE_X_RATE_GROUP)) *
Constants.ARC_SECONDS_TO_RADIANS / Constants.JULIAN_DAY;
final double yRate = Double.parseDouble(matcher.group(POLE_Y_RATE_GROUP)) *
Constants.ARC_SECONDS_TO_RADIANS / Constants.JULIAN_DAY;
final double dtu1 = Double.parseDouble(matcher.group(UT1_UTC_GROUP));
final double lod = Double.parseDouble(matcher.group(LOD_GROUP));
final double[] nro = new double[] {
Double.parseDouble(matcher.group(NUT_DX_GROUP)) * Constants.ARC_SECONDS_TO_RADIANS,
Double.parseDouble(matcher.group(NUT_DY_GROUP)) * Constants.ARC_SECONDS_TO_RADIANS
};
final double[] equinox = getConverter().toEquinox(date, nro[0], nro[1]);
return new EOPEntry(dc.getMJD(), dtu1, lod, x, y, xRate, yRate,
equinox[0], equinox[1], nro[0], nro[1],
getItrfVersion(), date);
}
}
}
}