<?xml version="1.0" encoding="UTF-8"?>
<!-- 
EGGX SIGMET 04 VALID 251600/252200 EGRR-
EGGX SHANWICK OCEANIC FIR VA ERUPTION MT H HEKLA PSN N6359 W01940 VA CLD OBS 1600Z 
SFC/FL550 N OF N6100 W01000 – N5900 W01300 – N6100 W01900 MOV S 60KT NC VA CLD 
FCST 2200Z SFC/FL550 N OF N6100 W01100 – N5800 W01400 – N6100 W01600=
-->
<!-- note: year and month of this SIGMET unknown; YYYY and MM used in place of actual values -->
<iwxxm:VolcanicAshSIGMET xmlns:iwxxm="http://icao.int/iwxxm/1.0RC2"
    xmlns:saf="http://icao.int/saf/1.0RC2"
    xmlns:metce="http://def.wmo.int/metce/2013" 
    xmlns:om="http://www.opengis.net/om/2.0"
    xmlns:sam="http://www.opengis.net/sampling/2.0"
    xmlns:sams="http://www.opengis.net/samplingSpatial/2.0"
    xmlns:gml="http://www.opengis.net/gml/3.2" 
    xmlns:gmd="http://www.isotc211.org/2005/gmd"
    xmlns:gco="http://www.isotc211.org/2005/gco" 
    xmlns:xlink="http://www.w3.org/1999/xlink"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://icao.int/iwxxm/1.0RC2 http://schemas.wmo.int/iwxxm/1.0RC2/iwxxm.xsd
    http://def.wmo.int/metce/2013 http://schemas.wmo.int/metce/1.0RC2/metce.xsd"
    gml:id="va-sigmet-EGXX-YYYYMM25T160000Z"
    status="NORMAL">
    <iwxxm:issuingAirTrafficServicesUnit>
        <saf:Unit gml:id="uuid.51cd8be0-b72e-11e2-9e96-0800200c9a66">
            <gml:identifier codeSpace="urn:uuid:">51cd8be0-b72e-11e2-9e96-0800200c9a66</gml:identifier>
            <saf:name>SHANWICK OCEANIC AREA CONTROL CENTRE</saf:name>
            <saf:type>ATCC</saf:type>
            <saf:designator>EGXX</saf:designator>
        </saf:Unit>
    </iwxxm:issuingAirTrafficServicesUnit>
    <iwxxm:originatingMeteorologicalWatchOffice>
        <saf:Unit gml:id="uuid.7abf6b40-b72e-11e2-9e96-0800200c9a66">
            <gml:identifier codeSpace="urn:uuid:">7abf6b40-b72e-11e2-9e96-0800200c9a66</gml:identifier>
            <saf:name>UK METEOROLOGICAL OFFICE - EXETER</saf:name>
            <saf:type>MWO</saf:type>
            <saf:designator>EGRR</saf:designator>
        </saf:Unit>
    </iwxxm:originatingMeteorologicalWatchOffice>
    <iwxxm:sequenceNumber>4</iwxxm:sequenceNumber>
    <iwxxm:validPeriod>
        <gml:TimePeriod gml:id="tp-25T16Z-25T22Z">
            <gml:beginPosition>YYYY-MM-25T16:00:00Z</gml:beginPosition>
            <gml:endPosition>YYYY-MM-25T22:00:00Z</gml:endPosition>
        </gml:TimePeriod>
    </iwxxm:validPeriod>
    <iwxxm:phenomenon xlink:href="http://codes.wmo.int/49-2/SigWxPhenomena/VA" xlink:title="Volcanic Ash"/>
    <iwxxm:analysis>
        <om:OM_Observation gml:id="va-position-and-motion-EGXX-YYYYMM25T16Z">
            <om:type xlink:href="http://codes.wmo.int/49-2/observation-type/IWXXM/1.0/SIGMETEvolvingConditionAnalysis"/>
            <om:phenomenonTime>
                <gml:TimeInstant gml:id="ti-25T16Z">
                    <gml:timePosition>YYYY-MM-25T16:00:00Z</gml:timePosition>
                </gml:TimeInstant>
            </om:phenomenonTime>
            <om:resultTime xlink:href="#ti-25T16Z"/>
            <om:validTime xlink:href="#tp-25T16Z-25T22Z"/>
            <om:procedure>
                <metce:Process gml:id="p-49-2-va-sigmet">
                    <gml:description>WMO No. 49 Volume 2 Meteorological Service for International Air Navigation 
                                     [C.3.1.]7 SIGMET AND AIRMET INFORMATION, AERODROME WARNINGS AND WIND SHEAR 
                                     WARNINGS AND ALERTS
                    </gml:description>
                </metce:Process>
            </om:procedure>
            <om:observedProperty
                xlink:href="http://codes.wmo.int/49-2/SigWxPhenomena/VA"
                xlink:title="Volcanic ash"/>
            <om:featureOfInterest>
                <sams:SF_SpatialSamplingFeature gml:id="ss-SHANWICK_OCA">
                    <sam:type xlink:href="http://www.opengis.net/def/samplingFeatureType/OGC-OM/2.0/SF_SamplingSurface"/>
                    <sam:sampledFeature>
                        <saf:Airspace gml:id="uuid.37a7f1d0-b731-11e2-9e96-0800200c9a66">
                            <gml:identifier codeSpace="urn:uuid:">37a7f1d0-b731-11e2-9e96-0800200c9a66</gml:identifier>
                            <saf:type>FIR</saf:type>
                            <saf:designator>EGXX</saf:designator>
                            <saf:name>SHANWICK OCEANIC FLIGHT INFORMATION REGION</saf:name>
                            <saf:geometryComponent>
                                <saf:AirspaceVolume gml:id="av-SHANWICK_OCA">
                                    <!-- note that upper limit and lower limit of the airspace volume are excluded - 
                                         implying that the volume extends from ground/sea surface to upper limit of aeronautical operations -->
                                    <saf:horizontalProjection>
                                        <gml:Polygon gml:id="boundary-geometry-SHANWICK_OCA"
                                            uomLabels="deg deg"
                                            axisLabels="Lat Lon" 
                                            srsDimension="2"
                                            srsName="http://www.opengis.net/def/crs/EPSG/0/4326">
                                            <gml:exterior>
                                                <gml:LinearRing>
                                                    <!-- SHANWICK FIR boundary (positions defined based on reference to map so possibly incorrect) -->
                                                    <gml:posList>
                                                        60.0 -30.0 
                                                        60.0 -10.0 
                                                        54.0 -10.0 
                                                        53.0 -15.0 
                                                        51.0 -15.0 
                                                        51.0 -8.0 
                                                        45.0 -8.0 
                                                        45.0 -30.0 
                                                        60.0 -30.0
                                                    </gml:posList>
                                                </gml:LinearRing>
                                            </gml:exterior>
                                        </gml:Polygon>
                                    </saf:horizontalProjection>
                                </saf:AirspaceVolume>
                            </saf:geometryComponent>
                        </saf:Airspace>
                    </sam:sampledFeature>
                    <sams:shape xlink:href="#boundary-geometry-SHANWICK_OCA"/>
                </sams:SF_SpatialSamplingFeature>
            </om:featureOfInterest>
            <om:result>
                <iwxxm:EvolvingMeteorologicalCondition gml:id="emc-va-obs-EGXX-YYYYMM25T16Z" intensityChange="NO_CHANGE">
                    <iwxxm:directionOfMotion uom="deg">180</iwxxm:directionOfMotion>
                    <iwxxm:geometry>
                        <saf:AirspaceVolume gml:id="av-va-obs-position-EGXX-YYYYMM25T16Z">
                            <!-- omitted lower-limit implies that the volcanic ash cloud extends to ground/sea surface -->
                            <saf:upperLimit uom="[ft_i]">55000</saf:upperLimit>
                            <saf:upperLimitReference>STD</saf:upperLimitReference>
                            <saf:horizontalProjection>
                                <gml:Polygon gml:id="polygon-va-obs-position-EGXX-YYYYMM25T16Z"
                                    uomLabels="deg deg"
                                    axisLabels="Lat Lon" 
                                    srsDimension="2"
                                    srsName="http://www.opengis.net/def/crs/EPSG/0/4326">
                                    <gml:exterior>
                                        <gml:LinearRing>
                                            <!-- bounding polygon clipped to edge of FIR @ 60N -->
                                            <gml:posList>
                                                60.0 -11.5 
                                                59.0 -13.0 
                                                60.0 -16.0 
                                                60.0 -11.5
                                            </gml:posList>
                                        </gml:LinearRing>
                                    </gml:exterior></gml:Polygon>
                            </saf:horizontalProjection>
                        </saf:AirspaceVolume>
                    </iwxxm:geometry>
                    <iwxxm:speedOfMotion uom="knot">60</iwxxm:speedOfMotion>
                </iwxxm:EvolvingMeteorologicalCondition>
            </om:result>
        </om:OM_Observation>
    </iwxxm:analysis>
    <iwxxm:forecastPositionAnalysis>
        <om:OM_Observation gml:id="va-forecast-position-EGXX-YYYYMM25T22Z">
            <om:type xlink:href="http://codes.wmo.int/49-2/observation-type/IWXXM/1.0/SIGMETPositionAnalysis"/>
            <om:phenomenonTime>
                <gml:TimeInstant gml:id="ti-25T22Z">
                    <gml:timePosition>YYYY-MM-25T22:00:00Z</gml:timePosition>
                </gml:TimeInstant>
            </om:phenomenonTime>
            <om:resultTime xlink:href="#ti-25T16Z"/>
            <om:validTime xlink:href="#tp-25T16Z-25T22Z"/>
            <om:procedure xlink:href="#p-49-2-va-sigmet"/>
            <om:observedProperty
                xlink:href="http://codes.wmo.int/49-2/SigWxPhenomena/VA"
                xlink:title="Volcanic ash"/>
            <om:featureOfInterest xlink:href="#ss-SHANWICK_OCA"/>
            <om:result>
                <iwxxm:MeteorologicalPositionCollection gml:id="mpc-EGXX-YYYYMM25T16Z">
                    <iwxxm:member>
                        <iwxxm:MeteorologicalPosition gml:id="mp-va-fcst-EGXX-YYYYMM25T16Z">
                            <iwxxm:geometry>
                                <saf:AirspaceVolume gml:id="av-va-fcst-position-EGXX-YYYYMM25T22Z">
                                    <!-- omitted lower-limit implies that the volcanic ash cloud extends to ground/sea surface -->
                                    <saf:upperLimit uom="[ft_i]">55000</saf:upperLimit>
                                    <saf:upperLimitReference>STD</saf:upperLimitReference>
                                    <saf:horizontalProjection>
                                        <gml:Polygon gml:id="polygon-va-fcst-position-EGXX-YYYYMM25T22Z"
                                            uomLabels="deg deg"
                                            axisLabels="Lat Lon" 
                                            srsDimension="2"
                                            srsName="http://www.opengis.net/def/crs/EPSG/0/4326">
                                            <gml:exterior>
                                                <gml:LinearRing>
                                                    <!-- bounding polygon clipped to edge of FIR @ 60N -->
                                                    <gml:posList>
                                                        60.0 -12.0 
                                                        58.0 -14.0 
                                                        60.0 -15.35 
                                                        60.0 -12.0
                                                    </gml:posList>
                                                </gml:LinearRing>
                                            </gml:exterior></gml:Polygon>
                                    </saf:horizontalProjection>
                                </saf:AirspaceVolume>
                            </iwxxm:geometry>
                        </iwxxm:MeteorologicalPosition>
                    </iwxxm:member>
                </iwxxm:MeteorologicalPositionCollection>
            </om:result>
        </om:OM_Observation>
    </iwxxm:forecastPositionAnalysis>
    <iwxxm:eruptingVolcano>
        <metce:Volcano gml:id="v-MT-HEKLA">
            <metce:name>MT HEKLA</metce:name>
            <metce:position>
                <gml:Point gml:id="ref-point-MT-HEKLA"
                    uomLabels="deg deg"
                    axisLabels="Lat Lon" 
                    srsDimension="2"
                    srsName="http://www.opengis.net/def/crs/EPSG/0/4326">
                    <gml:pos>63.59 -19.40</gml:pos>
                </gml:Point>
            </metce:position>
        </metce:Volcano>
    </iwxxm:eruptingVolcano>
</iwxxm:VolcanicAshSIGMET>
