MeanTheory.java

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package org.orekit.propagation.conversion.osc2mean;

import org.hipparchus.CalculusFieldElement;
import org.orekit.orbits.FieldOrbit;
import org.orekit.orbits.Orbit;

/**
 * Interface for theories that convert osculating into mean orbit.
 *
 * @author Pascal Parraud
 * @since 13.0
 */
public interface MeanTheory {

    /** Gets the name of the theory used for osculating to mean conversion.
     * @return the actual theory
     */
    String getTheoryName();

    /** Gets reference radius of the central body (m).
     * @return reference radius of the central body
     */
    double getReferenceRadius();

    /** Pre-treatment of the osculating orbit to be converted.
     * <p>By default, no pre-treatment is applied to the osculating orbit.</p>
     * @param osculating the osculating orbit to be treated
     * @return preprocessed osculating orbit
     */
    default Orbit preprocessing(Orbit osculating) {
        return osculating;
    }

    /** Rough initialization of the mean orbit.
     * <p>By default, the mean orbit is initialized with the osculating orbit.</p>
     * @param osculating the osculating orbit
     * @return initial mean orbit
     */
    default Orbit initialize(Orbit osculating) {
        return osculating;
    }

    /** Gets osculating orbit from mean orbit.
     * @param mean mean orbit
     * @return osculating orbit
     */
    Orbit meanToOsculating(Orbit mean);

    /** Post-treatment of the converted mean orbit.
     * <p>By default, the mean orbit returned is of the same
     * type as the osculating orbit to be converted.</p>
     * @param osculating the osculating orbit to be converted
     * @param mean the converted mean orbit
     * @return postprocessed mean orbit
     */
    default Orbit postprocessing(Orbit osculating, Orbit mean) {
        return osculating.getType().convertType(mean);
    }

    /** Pre-treatment of the osculating orbit to be converted.
     * <p>By default, no pre-treatment is applied to the osculating orbit.</p>
     * @param <T> type of the field elements
     * @param osculating the osculating orbit to be treated
     * @return preprocessed osculating orbit
     */
    default <T extends CalculusFieldElement<T>> FieldOrbit<T> preprocessing(FieldOrbit<T> osculating) {
        return osculating;
    }

    /** Rough initialization of the mean orbit.
     * <p>By default, the mean orbit is initialized with the osculating orbit.</p>
     * @param <T> type of the field elements
     * @param osculating the osculating orbit
     * @return initial mean orbit
     */
    default <T extends CalculusFieldElement<T>> FieldOrbit<T> initialize(FieldOrbit<T> osculating) {
        return osculating;
    }

    /** Gets osculating orbit from mean orbit.
     * @param <T> type of the field elements
     * @param mean mean orbit
     * @return osculating orbit
     */
    <T extends CalculusFieldElement<T>> FieldOrbit<T> meanToOsculating(FieldOrbit<T> mean);

    /** Post-treatment of the converted mean orbit.
     * <p>By default, the mean orbit returned is of the same
     * type as the osculating orbit to be converted.</p>
     * @param <T> type of the field elements
     * @param osculating the osculating orbit to be converted
     * @param mean the converted mean orbit
     * @return postprocessed mean orbit
     */
    default <T extends CalculusFieldElement<T>> FieldOrbit<T> postprocessing(FieldOrbit<T> osculating,
                                                                             FieldOrbit<T> mean) {
        return osculating.getType().convertType(mean);
    }

}