JB2008SpaceEnvironmentData.java
/* Copyright 2002-2022 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.models.earth.atmosphere.data;
import java.util.List;
import java.util.stream.Collectors;
import org.orekit.annotation.DefaultDataContext;
import org.orekit.data.DataContext;
import org.orekit.data.DataProvidersManager;
import org.orekit.errors.OrekitException;
import org.orekit.errors.OrekitMessages;
import org.orekit.models.earth.atmosphere.JB2008InputParameters;
import org.orekit.time.AbsoluteDate;
import org.orekit.time.TimeScale;
import org.orekit.utils.Constants;
import org.orekit.utils.ImmutableTimeStampedCache;
/**
* This class provides a container for the solar indices data required by the JB2008
* atmospheric model. This container only stores information provided in the SOLFSMY and DTCFILE text file
* provided by Space Environment Technologies. Therefore it doesn't provide the geomagnetic storm
* indices available in the SOLRESAP file.
* The {@link org.orekit.data.DataLoader} implementations and the parsing are handled by
* the {@link SOLFSMYDataLoader} {@link DtcDataLoader} classes.
* <p>
* Data are available on Space Environment Technologies'
* <a href="http://sol.spacenvironment.net/jb2008">website</a>.
*
* The work done for this class is based on the CssiSpaceWeatherData class
* by Clément Jonglez, the JB2008 interface by Pascal Parraud, and corrections for
* the CssiSpaceWeatherData implementation by Bryan Cazabonne and Evan Ward.
*
* @author Louis Aucouturier
* @since 11.2
*/
public class JB2008SpaceEnvironmentData implements JB2008InputParameters {
/** Default regular expression for supported names that works with test and published files for the SOLFSMY file. */
public static final String DEFAULT_SUPPORTED_NAMES_SOLFSMY = "(SOLFSMY)(.*)((\\.txt)|(\\.TXT))";
/** Default regular expression for supported names that works with test and published files for the DTCFILE file. */
public static final String DEFAULT_SUPPORTED_NAMES_DTC = "DTCFILE.TXT";
/** Serializable UID. */
private static final long serialVersionUID = 7735042547323407578L;
/** Size of the list. */
private static final int N_NEIGHBORS = 2;
/** Data set for SOLFSMY file. */
private final transient ImmutableTimeStampedCache<SOLFSMYDataLoader.LineParameters> dataSOL;
/** Data set for DTCFILE file. */
private final transient ImmutableTimeStampedCache<DtcDataLoader.LineParameters> dataDTC;
/** First available date. */
private final AbsoluteDate firstDate;
/** Last available date. */
private final AbsoluteDate lastDate;
/** Previous set of solar activity parameters. */
private SOLFSMYDataLoader.LineParameters previousParamSOL;
/** Current set of solar activity parameters. */
private SOLFSMYDataLoader.LineParameters nextParamSOL;
/** Previous set of solar activity parameters. */
private DtcDataLoader.LineParameters previousParamDTC;
/** Current set of solar activity parameters. */
private DtcDataLoader.LineParameters nextParamDTC;
/**
* Simple constructor. This constructor uses the default data context.
*
* @param supportedNamesSOL regular expression for SOLFSMY space weather files names
* with variations allowed between SOLFSMY and the file extension.
* @param supportedNamesDTC regular expression for DTCFILE files names
* with variations allowed between DTCFILE and the file extension.
*/
@DefaultDataContext
public JB2008SpaceEnvironmentData(final String supportedNamesSOL, final String supportedNamesDTC) {
this(supportedNamesSOL, supportedNamesDTC, DataContext.getDefault().getDataProvidersManager(),
DataContext.getDefault().getTimeScales().getUTC());
}
/**
* Constructor that allows specifying the source of the SOLFSMY space weather
* file.
* This constructor takes a supplementary argument, the supported names for DTCFILE,
* in order to setup the second loader.
*
* @param supportedNamesSOL regular expression for SOLFSMY space weather files names
* with variations allowed between SOLFSMY and the file extension.
* @param supportedNamesDTC regular expression for DTCFILE files names
* with variations allowed between DTCFILE and the file extension.
* @param dataProvidersManager provides access to auxiliary data files.
* @param utc UTC time scale.
*/
public JB2008SpaceEnvironmentData(final String supportedNamesSOL,
final String supportedNamesDTC,
final DataProvidersManager dataProvidersManager,
final TimeScale utc) {
// Load SOLFSMY data
final SOLFSMYDataLoader loaderSOL = new SOLFSMYDataLoader(utc);
dataProvidersManager.feed(supportedNamesSOL, loaderSOL);
dataSOL = new ImmutableTimeStampedCache<>(N_NEIGHBORS, loaderSOL.getDataSet());
// Load DTC data
final DtcDataLoader loaderDTC = new DtcDataLoader(utc);
dataProvidersManager.feed(supportedNamesDTC, loaderDTC);
dataDTC = new ImmutableTimeStampedCache<>(N_NEIGHBORS, loaderDTC.getDataSet());
// Because the two files are generated by the same organism,
// the first and last epochs are identical between the two files
firstDate = loaderSOL.getMinDate();
lastDate = loaderSOL.getMaxDate();
}
/** {@inheritDoc} */
public AbsoluteDate getMinDate() {
return firstDate;
}
/** {@inheritDoc} */
public AbsoluteDate getMaxDate() {
return lastDate;
}
/**
* Find the data bracketing a specified date in dataSOL.
*
* @param date date to bracket
*/
private void bracketDateSOL(final AbsoluteDate date) {
/**
* The presence of the shift in dates for checks on the validity of dates
* is here to enforce the lag on the parameters (5-day lag max for Y10 parameters).
* This lag is already present in the date parameter.
*/
final AbsoluteDate firstDateUsefulSOL = firstDate.shiftedBy(-5 * Constants.JULIAN_DAY);
if (date.durationFrom(firstDateUsefulSOL) < 0) {
throw new OrekitException(OrekitMessages.OUT_OF_RANGE_EPHEMERIDES_DATE_BEFORE,
date, firstDateUsefulSOL, lastDate, firstDateUsefulSOL.durationFrom(date));
}
if (date.durationFrom(lastDate) > 0) {
throw new OrekitException(OrekitMessages.OUT_OF_RANGE_EPHEMERIDES_DATE_AFTER,
date, firstDateUsefulSOL, lastDate, date.durationFrom(lastDate));
}
// don't search if the cached selection is fine
if (previousParamSOL != null && date.durationFrom(previousParamSOL.getDate()) > 0 &&
date.durationFrom(nextParamSOL.getDate()) <= 0) {
return;
}
final List<SOLFSMYDataLoader.LineParameters> neigbors = dataSOL.getNeighbors(date).collect(Collectors.toList());
previousParamSOL = neigbors.get(0);
nextParamSOL = neigbors.get(1);
}
/**
* Find the data bracketing a specified date in dataDTC.
*
* @param date date to bracket
*/
private void bracketDateDTC(final AbsoluteDate date) {
// No data lag
final AbsoluteDate firstDateUsefulDTC = firstDate;
if (date.durationFrom(firstDateUsefulDTC) < 0) {
throw new OrekitException(OrekitMessages.OUT_OF_RANGE_EPHEMERIDES_DATE_BEFORE,
date, firstDateUsefulDTC, lastDate, firstDateUsefulDTC.durationFrom(date));
}
if (date.durationFrom(lastDate) > 0) {
throw new OrekitException(OrekitMessages.OUT_OF_RANGE_EPHEMERIDES_DATE_AFTER,
date, firstDateUsefulDTC, lastDate, date.durationFrom(lastDate));
}
// don't search if the cached selection is fine
if (previousParamDTC != null && date.durationFrom(previousParamDTC.getDate()) > 0 &&
date.durationFrom(nextParamDTC.getDate()) <= 0) {
return;
}
final List<DtcDataLoader.LineParameters> neigbors = dataDTC.getNeighbors(date).collect(Collectors.toList());
previousParamDTC = neigbors.get(0);
nextParamDTC = neigbors.get(1);
}
/**
* Performs a linear interpolation between two values The weights are computed
* from the time delta between previous date, current date, next date.
*
* @param date the current date
* @param previousValue the value at previous date
* @param nextValue the value at next date
* @return the value interpolated for the current date
*/
private double getLinearInterpolationSOL(final AbsoluteDate date, final double previousValue, final double nextValue) {
// perform a linear interpolation
return linearInterpolation(date, previousValue, previousParamSOL.getDate(), nextValue, nextParamSOL.getDate());
}
/**
* Performs a linear interpolation between two values The weights are computed
* from the time delta between previous date, current date, next date.
*
* @param date the current date
* @param previousValue the value at previous date
* @param nextValue the value at next date
* @return the value interpolated for the current date
*/
private double getLinearInterpolationDTC(final AbsoluteDate date, final double previousValue, final double nextValue) {
// perform a linear interpolation
return linearInterpolation(date, previousValue, previousParamDTC.getDate(), nextValue, nextParamDTC.getDate());
}
/**
* Linear interpolation.
* @param date the current date
* @param previousValue the value at previous date
* @param previousDate the previous date
* @param nextValue the value at next date
* @param nextDate the next date
* @return the inteprolated value
*/
private double linearInterpolation(final AbsoluteDate date,
final double previousValue, final AbsoluteDate previousDate,
final double nextValue, final AbsoluteDate nextDate) {
// perform a linear interpolation
final double dt = nextDate.durationFrom(previousDate);
final double previousWeight = nextDate.durationFrom(date) / dt;
final double nextWeight = date.durationFrom(previousDate) / dt;
// returns the data interpolated at the date
return previousValue * previousWeight + nextValue * nextWeight;
}
/** {@inheritDoc} */
public double getF10(final AbsoluteDate date) {
// The date is shifted by 1 day as described in the JB2008 Model with a 1-day lag.
final AbsoluteDate workDate = date.shiftedBy(-Constants.JULIAN_DAY);
bracketDateSOL(workDate);
return getLinearInterpolationSOL(workDate, previousParamSOL.getF10(), nextParamSOL.getF10());
}
/** {@inheritDoc} */
public double getF10B(final AbsoluteDate date) {
// The date is shifted by 1 day as described in the JB2008 Model with a 1-day lag.
final AbsoluteDate workDate = date.shiftedBy(-Constants.JULIAN_DAY);
bracketDateSOL(workDate);
return getLinearInterpolationSOL(workDate, previousParamSOL.getF10B(), nextParamSOL.getF10B());
}
/** {@inheritDoc} */
public double getS10(final AbsoluteDate date) {
// The date is shifted by 1 day as described in the JB2008 Model with a 1-day lag.
final AbsoluteDate workDate = date.shiftedBy(-Constants.JULIAN_DAY);
bracketDateSOL(workDate);
return getLinearInterpolationSOL(workDate, previousParamSOL.getS10(), nextParamSOL.getS10());
}
/** {@inheritDoc} */
public double getS10B(final AbsoluteDate date) {
// The date is shifted by 1 day as described in the JB2008 Model with a 1-day lag.
final AbsoluteDate workDate = date.shiftedBy(-Constants.JULIAN_DAY);
bracketDateSOL(workDate);
return getLinearInterpolationSOL(workDate, previousParamSOL.getS10B(), nextParamSOL.getS10B());
}
/** {@inheritDoc} */
public double getXM10(final AbsoluteDate date) {
// The date is shifted by 2 day as described in the JB2008 Model with a 2-day lag.
final AbsoluteDate workDate = date.shiftedBy(-2.0 * Constants.JULIAN_DAY);
bracketDateSOL(workDate);
return getLinearInterpolationSOL(workDate, previousParamSOL.getXM10(), nextParamSOL.getXM10());
}
/** {@inheritDoc} */
public double getXM10B(final AbsoluteDate date) {
// The date is shifted by 2 day as described in the JB2008 Model with a 2-day lag.
final AbsoluteDate workDate = date.shiftedBy(-2.0 * Constants.JULIAN_DAY);
bracketDateSOL(workDate);;
return getLinearInterpolationSOL(workDate, previousParamSOL.getXM10B(), nextParamSOL.getXM10B());
}
/** {@inheritDoc} */
public double getY10(final AbsoluteDate date) {
// The date is shifted by 5 day as described in the JB2008 Model with a 5-day lag.
final AbsoluteDate workDate = date.shiftedBy(-5.0 * Constants.JULIAN_DAY);
bracketDateSOL(workDate);
return getLinearInterpolationSOL(workDate, previousParamSOL.getY10(), nextParamSOL.getY10());
}
/** {@inheritDoc} */
public double getY10B(final AbsoluteDate date) {
// The date is shifted by 5 day as described in the JB2008 Model with a 5-day lag.
final AbsoluteDate workDate = date.shiftedBy(-5.0 * Constants.JULIAN_DAY);
bracketDateSOL(workDate);
return getLinearInterpolationSOL(workDate, previousParamSOL.getY10B(), nextParamSOL.getY10B());
}
/** {@inheritDoc} */
public double getDSTDTC(final AbsoluteDate date) {
bracketDateDTC(date);
return getLinearInterpolationDTC(date, previousParamDTC.getDSTDTC(), nextParamDTC.getDSTDTC());
}
}