VersionedITRFProvider.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,
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*/
package org.orekit.frames;
import java.io.Serializable;
import java.util.concurrent.atomic.AtomicReference;
import org.hipparchus.CalculusFieldElement;
import org.orekit.annotation.DefaultDataContext;
import org.orekit.data.DataContext;
import org.orekit.time.AbsoluteDate;
import org.orekit.time.FieldAbsoluteDate;
import org.orekit.time.TimeScale;
/** Provider for a specific version of International Terrestrial Reference Frame.
* <p>
* This class ensure the ITRF it defines is a specific version, regardless of
* the version of the underlying {@link EOPEntry Earth Orientation Parameters}.
* </p>
* @author Luc Maisonobe
* @since 9.2
*/
class VersionedITRFProvider implements EOPBasedTransformProvider {
/** Serializable UID. */
private static final long serialVersionUID = 20180403L;
/** ITRF version this provider should generate. */
private final ITRFVersion version;
/** Raw ITRF provider. */
private final ITRFProvider rawProvider;
/** Converter between different ITRF versions. */
private final AtomicReference<ITRFVersion.Converter> converter;
/** TT time scale. */
private final TimeScale tt;
/** Simple constructor.
* @param version ITRF version this provider should generate
* @param rawProvider raw ITRF provider
* @param tt TT time scale.
*/
VersionedITRFProvider(final ITRFVersion version,
final ITRFProvider rawProvider,
final TimeScale tt) {
this.version = version;
this.rawProvider = rawProvider;
this.converter = new AtomicReference<>();
this.tt = tt;
}
/** Get the ITRF version.
* @return ITRF version
*/
public ITRFVersion getITRFVersion() {
return version;
}
/** {@inheritDoc} */
@Override
public EOPHistory getEOPHistory() {
return rawProvider.getEOPHistory();
}
/** {@inheritDoc} */
@Override
public VersionedITRFProvider getNonInterpolatingProvider() {
return new VersionedITRFProvider(version, rawProvider.getNonInterpolatingProvider(), tt);
}
/** {@inheritDoc} */
@Override
public Transform getTransform(final AbsoluteDate date) {
// get the transform from the current EOP
final Transform rawTransform = rawProvider.getTransform(date);
// add the conversion layer
final ITRFVersion.Converter converterForDate = getConverter(date);
if (converterForDate == null) {
return rawTransform;
} else {
return new Transform(date, rawTransform, converterForDate.getTransform(date));
}
}
/** {@inheritDoc} */
@Override
public KinematicTransform getKinematicTransform(final AbsoluteDate date) {
// get the transform from the current EOP
final KinematicTransform rawTransform = rawProvider.getKinematicTransform(date);
// add the conversion layer
final ITRFVersion.Converter converterForDate = getConverter(date);
if (converterForDate == null) {
return rawTransform;
} else {
return KinematicTransform.compose(date, rawTransform, converterForDate.getKinematicTransform(date));
}
}
/** {@inheritDoc} */
@Override
public StaticTransform getStaticTransform(final AbsoluteDate date) {
// get the transform from the current EOP
final StaticTransform rawTransform = rawProvider.getStaticTransform(date);
// add the conversion layer
final ITRFVersion.Converter converterForDate = getConverter(date);
if (converterForDate == null) {
return rawTransform;
} else {
return StaticTransform.compose(
date,
rawTransform,
converterForDate.getStaticTransform(date));
}
}
/** {@inheritDoc} */
@Override
public <T extends CalculusFieldElement<T>> FieldTransform<T> getTransform(final FieldAbsoluteDate<T> date) {
// get the transform from the current EOP
final FieldTransform<T> rawTransform = rawProvider.getTransform(date);
// add the conversion layer
final ITRFVersion.Converter converterForDate = getConverter(date.toAbsoluteDate());
if (converterForDate == null) {
return rawTransform;
} else {
return new FieldTransform<>(date, rawTransform, converterForDate.getTransform(date));
}
}
/** {@inheritDoc} */
@Override
public <T extends CalculusFieldElement<T>> FieldKinematicTransform<T> getKinematicTransform(final FieldAbsoluteDate<T> date) {
// get the transform from the current EOP
final FieldKinematicTransform<T> rawTransform = rawProvider.getKinematicTransform(date);
// add the conversion layer
final ITRFVersion.Converter converterForDate = getConverter(date.toAbsoluteDate());
if (converterForDate == null) {
return rawTransform;
} else {
return FieldKinematicTransform.compose(date, rawTransform, converterForDate.getKinematicTransform(date));
}
}
/** {@inheritDoc} */
@Override
public <T extends CalculusFieldElement<T>> FieldStaticTransform<T> getStaticTransform(final FieldAbsoluteDate<T> date) {
// get the transform from the current EOP
final FieldStaticTransform<T> rawTransform = rawProvider.getStaticTransform(date);
// add the conversion layer
final ITRFVersion.Converter converterForDate = getConverter(date.toAbsoluteDate());
if (converterForDate == null) {
return rawTransform;
} else {
return FieldStaticTransform.compose(
date,
rawTransform,
converterForDate.getStaticTransform(date));
}
}
/** Get a converter for the date.
* @param date date to check
* @return converter that should be applied for this date, or null
* if no converter is needed
*/
private ITRFVersion.Converter getConverter(final AbsoluteDate date) {
// check if the current EOP already provides the version we want
final ITRFVersion rawVersion = getEOPHistory().getITRFVersion(date);
if (rawVersion == version) {
// we already have what we need
return null;
}
final ITRFVersion.Converter existing = converter.get();
if (existing != null && existing.getOrigin() == rawVersion) {
// the current converter can handle this date
return existing;
}
// we need to create a new converter from raw version to desired version
final ITRFVersion.Converter newConverter =
ITRFVersion.getConverter(rawVersion, version, tt);
converter.compareAndSet(null, newConverter);
return newConverter;
}
/** Replace the instance with a data transfer object for serialization.
* @return data transfer object that will be serialized
*/
@DefaultDataContext
private Object writeReplace() {
return new DataTransferObject(version, rawProvider);
}
/** Internal class used only for serialization. */
@DefaultDataContext
private static class DataTransferObject implements Serializable {
/** Serializable UID. */
private static final long serialVersionUID = 20180403L;
/** ITRF version this provider should generate. */
private final ITRFVersion version;
/** Raw ITRF provider. */
private final ITRFProvider rawProvider;
/** Simple constructor.
* @param version ITRF version this provider should generate
* @param rawProvider raw ITRF provider
*/
DataTransferObject(final ITRFVersion version, final ITRFProvider rawProvider) {
this.version = version;
this.rawProvider = rawProvider;
}
/** Replace the deserialized data transfer object with a {@link VersionedITRFProvider}.
* @return replacement {@link VersionedITRFProvider}
*/
private Object readResolve() {
return new VersionedITRFProvider(version, rawProvider,
DataContext.getDefault().getTimeScales().getTT());
}
}
}