OrbitCovarianceHistoryWriter.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.files.ccsds.ndm.odm.ocm;
import java.io.IOException;
import java.util.List;
import org.hipparchus.linear.RealMatrix;
import org.hipparchus.util.FastMath;
import org.orekit.files.ccsds.definitions.TimeConverter;
import org.orekit.files.ccsds.section.AbstractWriter;
import org.orekit.files.ccsds.utils.FileFormat;
import org.orekit.files.ccsds.utils.generation.Generator;
import org.orekit.utils.AccurateFormatter;
import org.orekit.utils.units.Unit;
/** Writer for covariance history data.
* @author Luc Maisonobe
* @since 11.0
*/
class OrbitCovarianceHistoryWriter extends AbstractWriter {
/** Covariance history block. */
private final OrbitCovarianceHistory history;
/** Converter for dates. */
private final TimeConverter timeConverter;
/** Create a writer.
* @param covarianceHistory covariance history to write
* @param timeConverter converter for dates
*/
OrbitCovarianceHistoryWriter(final OrbitCovarianceHistory covarianceHistory,
final TimeConverter timeConverter) {
super(OcmDataSubStructureKey.cov.name(), OcmDataSubStructureKey.COV.name());
this.history = covarianceHistory;
this.timeConverter = timeConverter;
}
/** {@inheritDoc} */
@Override
protected void writeContent(final Generator generator) throws IOException {
// covariance history block
final OrbitCovarianceHistoryMetadata metadata = history.getMetadata();
generator.writeComments(metadata.getComments());
// identifiers
generator.writeEntry(OrbitCovarianceHistoryMetadataKey.COV_ID.name(), metadata.getCovID(), null, false);
generator.writeEntry(OrbitCovarianceHistoryMetadataKey.COV_PREV_ID.name(), metadata.getCovPrevID(), null, false);
generator.writeEntry(OrbitCovarianceHistoryMetadataKey.COV_NEXT_ID.name(), metadata.getCovNextID(), null, false);
generator.writeEntry(OrbitCovarianceHistoryMetadataKey.COV_BASIS.name(), metadata.getCovBasis(), null, false);
generator.writeEntry(OrbitCovarianceHistoryMetadataKey.COV_BASIS_ID.name(), metadata.getCovBasisID(), null, false);
// references
generator.writeEntry(OrbitCovarianceHistoryMetadataKey.COV_REF_FRAME.name(), metadata.getCovReferenceFrame().getName(), null, false);
if (!metadata.getCovFrameEpoch().equals(timeConverter.getReferenceDate()) &&
metadata.getCovReferenceFrame().asOrbitRelativeFrame() == null &&
metadata.getCovReferenceFrame().asSpacecraftBodyFrame() == null) {
generator.writeEntry(OrbitCovarianceHistoryMetadataKey.COV_FRAME_EPOCH.name(), timeConverter, metadata.getCovFrameEpoch(), true, false);
}
// scaling
generator.writeEntry(OrbitCovarianceHistoryMetadataKey.COV_SCALE_MIN.name(), metadata.getCovScaleMin(), Unit.ONE, false);
generator.writeEntry(OrbitCovarianceHistoryMetadataKey.COV_SCALE_MAX.name(), metadata.getCovScaleMax(), Unit.ONE, false);
generator.writeEntry(OrbitCovarianceHistoryMetadataKey.COV_CONFIDENCE.name(), metadata.getCovConfidence(), Unit.PERCENT, false);
// elements
generator.writeEntry(OrbitCovarianceHistoryMetadataKey.COV_TYPE.name(), metadata.getCovType(), false);
generator.writeEntry(OrbitCovarianceHistoryMetadataKey.COV_ORDERING.name(), metadata.getCovOrdering(), false);
generator.writeEntry(OrbitCovarianceHistoryMetadataKey.COV_UNITS.name(), generator.unitsListToString(metadata.getCovUnits()), null, false);
// data
final List<Unit> units = metadata.getCovType().getUnits();
for (final OrbitCovariance covariance : history.getCovariances()) {
final RealMatrix matrix = covariance.getMatrix();
final Ordering ordering = metadata.getCovOrdering();
final CovarianceIndexer indexer = new CovarianceIndexer(units.size());
final StringBuilder line = new StringBuilder();
line.append(generator.dateToString(timeConverter, covariance.getDate()));
for (int k = 0; k < ordering.nbElements(units.size()); ++k) {
final int i = indexer.getRow();
final int j = indexer.getColumn();
final double cij;
if (indexer.isCrossCorrelation()) {
// we need to compute the cross-correlation
cij = matrix.getEntry(i, j) /
FastMath.sqrt(matrix.getEntry(i, i) * matrix.getEntry(j, j));
} else {
// we need to get the covariance
cij = units.get(i).fromSI(units.get(j).fromSI(matrix.getEntry(i, j)));
}
line.append(' ');
line.append(AccurateFormatter.format(cij));
ordering.update(indexer);
}
if (generator.getFormat() == FileFormat.XML) {
generator.writeEntry(Ocm.COV_LINE, line.toString(), null, true);
} else {
generator.writeRawData(line);
generator.newLine();
}
}
}
}