IAUPole.java

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package org.orekit.bodies;

import java.io.Serializable;

import org.hipparchus.CalculusFieldElement;
import org.hipparchus.geometry.euclidean.threed.FieldVector3D;
import org.hipparchus.geometry.euclidean.threed.Vector3D;
import org.orekit.time.AbsoluteDate;
import org.orekit.time.FieldAbsoluteDate;

/** Interface for IAU pole and prime meridian orientations.
 * <p>
 * This interface defines methods compliant with the report of the
 * IAU/IAG Working Group on Cartographic Coordinates and Rotational
 * Elements of the Planets and Satellites (WGCCRE). These definitions
 * are common for all recent versions of this report published every
 * three years.
 * </p>
 * <p>
 * The precise values of pole direction and W angle coefficients may vary
 * from publication year as models are adjusted. The latest value of
 * constants for implementing this interface can be found in the <a
 * href="http://astrogeology.usgs.gov/Projects/WGCCRE/">working group
 * site</a>.
 * </p>
 * @see CelestialBodies
 * @author Luc Maisonobe
 */
public interface IAUPole extends Serializable {

    /** Get the body North pole direction in ICRF frame.
     * @param date current date
     * @return body North pole direction in ICRF frame
     */
    Vector3D getPole(AbsoluteDate date);

    /** Get the body North pole direction in ICRF frame.
     * @param date current date
     * @param <T> type of the field elements
     * @return body North pole direction in ICRF frame
     * @since 9.0
     */
    <T extends CalculusFieldElement<T>> FieldVector3D<T> getPole(FieldAbsoluteDate<T> date);

    /** Get the body Q Node direction in ICRF frame.
     * @param date current date
     * @return body Q Node direction in ICRF frame
     * @since 9.1
     */
    default Vector3D getNode(AbsoluteDate date) {
        return Vector3D.crossProduct(Vector3D.PLUS_K, getPole(date));
    }

    /** Get the body Q Node direction in ICRF frame.
     * @param date current date
     * @param <T> type of the field elements
     * @return body Q Node direction in ICRF frame
     * @since 9.1
     */
    default <T extends CalculusFieldElement<T>> FieldVector3D<T> getNode(FieldAbsoluteDate<T> date) {
        return FieldVector3D.crossProduct(FieldVector3D.getPlusK(date.getField()), getPole(date));
    }

    /** Get the prime meridian angle.
     * <p>
     * The prime meridian angle is the angle between the Q node and the
     * prime meridian. represents the body rotation.
     * </p>
     * @param date current date
     * @return prime meridian vector
     */
    double getPrimeMeridianAngle(AbsoluteDate date);

    /** Get the prime meridian angle.
     * <p>
     * The prime meridian angle is the angle between the Q node and the
     * prime meridian. represents the body rotation.
     * </p>
     * @param date current date
     * @param <T> type of the field elements
     * @return prime meridian vector
     * @since 9.0
     */
    <T extends CalculusFieldElement<T>> T getPrimeMeridianAngle(FieldAbsoluteDate<T> date);

}