001/*
002 *    GeoAPI - Java interfaces for OGC/ISO standards
003 *    Copyright © 2003-2023 Open Geospatial Consortium, Inc.
004 *    http://www.geoapi.org
005 *
006 *    Licensed under the Apache License, Version 2.0 (the "License");
007 *    you may not use this file except in compliance with the License.
008 *    You may obtain a copy of the License at
009 *
010 *        http://www.apache.org/licenses/LICENSE-2.0
011 *
012 *    Unless required by applicable law or agreed to in writing, software
013 *    distributed under the License is distributed on an "AS IS" BASIS,
014 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 *    See the License for the specific language governing permissions and
016 *    limitations under the License.
017 */
018package org.opengis.referencing.datum;
019
020import java.util.Map;
021import java.util.Optional;
022import org.opengis.annotation.UML;
023
024import static org.opengis.annotation.Obligation.*;
025import static org.opengis.annotation.Specification.*;
026
027
028/**
029 * Identification of a particular reference level surface used as a zero-height surface.
030 * The description includes its position with respect to the planet for any of the height
031 * types recognized by the ISO 19111 standard.
032 *
033 * <p>There are several types of vertical reference frames, and each may place constraints
034 * on the {@linkplain org.opengis.referencing.cs.CoordinateSystemAxis Coordinate Axis} with which
035 * it is combined to create a {@linkplain org.opengis.referencing.crs.VerticalCRS Vertical CRS}.</p>
036 *
037 * @author  OGC Topic 2 (for abstract model and documentation)
038 * @author  Martin Desruisseaux (IRD, Geomatys)
039 * @version 3.1
040 * @since   1.0
041 *
042 * @see DatumAuthorityFactory#createVerticalDatum(String)
043 * @see DatumFactory#createVerticalDatum(Map, RealizationMethod)
044 */
045@UML(identifier="VerticalReferenceFrame", specification=ISO_19111)
046public interface VerticalDatum extends Datum {
047    /**
048     * Returns the method through which this vertical reference frame is realized.
049     *
050     * @return method through which this vertical reference frame is realized.
051     *
052     * @since 3.1
053     */
054    @UML(identifier="realizationMethod", obligation=OPTIONAL, specification=ISO_19111)
055    default Optional<RealizationMethod> getRealizationMethod() {
056        return Optional.empty();
057    }
058
059    /**
060     * The type of this vertical datum.
061     *
062     * @return the type of this vertical datum.
063     *
064     * @deprecated Replaced by {@link #getRealizationMethod()} in ISO 19111:2019.
065     */
066    @Deprecated(since = "3.1")
067    @UML(identifier="vertDatumType", obligation=MANDATORY, specification=ISO_19111, version=2003)
068    default VerticalDatumType getVerticalDatumType() {
069        return VerticalDatumType.from(getRealizationMethod().orElse(null));
070    }
071}