MeanKeplerianElementsWriter.java

/* Copyright 2002-2025 CS GROUP
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 * 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
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 * distributed under the License is distributed on an "AS IS" BASIS,
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package org.orekit.files.ccsds.ndm.odm.omm;

import java.io.IOException;

import org.orekit.files.ccsds.definitions.TimeConverter;
import org.orekit.files.ccsds.definitions.Units;
import org.orekit.files.ccsds.ndm.odm.KeplerianElements;
import org.orekit.files.ccsds.ndm.odm.KeplerianElementsKey;
import org.orekit.files.ccsds.section.AbstractWriter;
import org.orekit.files.ccsds.utils.generation.Generator;
import org.orekit.utils.units.Unit;

/** Writer for Keplerian elements data in OMM files.
 * @author Luc Maisonobe
 * @since 11.0
 */
class MeanKeplerianElementsWriter extends AbstractWriter {

    /** Keplerian elements block. */
    private final KeplerianElements keplerianElements;

    /** Converter for dates. */
    private final TimeConverter timeConverter;

    /** Flag for SGP/SDP mean element theory. */
    private final boolean theoryIsSgpSdp;

    /** Create a writer.
     * @param xmlTag name of the XML tag surrounding the section
     * @param kvnTag name of the KVN tag surrounding the section (may be null)
     * @param keplerianElements Keplerian elements to write
     * @param timeConverter converter for dates
     * @param theoryIsSgpSdp if true, mean element theory in SGP or SDP
     */
    MeanKeplerianElementsWriter(final String xmlTag, final String kvnTag,
                                final KeplerianElements keplerianElements,
                                final TimeConverter timeConverter,
                                final boolean theoryIsSgpSdp) {
        super(xmlTag, kvnTag);
        this.keplerianElements = keplerianElements;
        this.timeConverter     = timeConverter;
        this.theoryIsSgpSdp    = theoryIsSgpSdp;
    }

    /** {@inheritDoc} */
    @Override
    protected void writeContent(final Generator generator) throws IOException {

        // Keplerian elements block
        generator.writeComments(keplerianElements.getComments());
        generator.writeEntry(KeplerianElementsKey.EPOCH.name(), timeConverter, keplerianElements.getEpoch(), true, true);
        if (theoryIsSgpSdp) {
            generator.writeEntry(KeplerianElementsKey.MEAN_MOTION.name(), keplerianElements.getMeanMotion(), Units.REV_PER_DAY, true);
        } else {
            generator.writeEntry(KeplerianElementsKey.SEMI_MAJOR_AXIS.name(), keplerianElements.getA(), Unit.KILOMETRE, true);
        }
        generator.writeEntry(KeplerianElementsKey.ECCENTRICITY.name(),      keplerianElements.getE(), Unit.ONE,          true);
        generator.writeEntry(KeplerianElementsKey.INCLINATION.name(),       keplerianElements.getI(), Unit.DEGREE,       true);
        generator.writeEntry(KeplerianElementsKey.RA_OF_ASC_NODE.name(),    keplerianElements.getRaan(), Unit.DEGREE,    true);
        generator.writeEntry(KeplerianElementsKey.ARG_OF_PERICENTER.name(), keplerianElements.getPa(), Unit.DEGREE,      true);
        generator.writeEntry(KeplerianElementsKey.MEAN_ANOMALY.name(),      keplerianElements.getAnomaly(), Unit.DEGREE, true);
        generator.writeEntry(KeplerianElementsKey.GM.name(),                keplerianElements.getMu(), Units.KM3_PER_S2, false);

    }

}