Circle by Center Point

Circle by Center Point

Full circles are also used in order to define the geometry of certain airspace in the AI domain. They can be directly encoded using the gml:CircleByCenterPoint. It is quite deep in the structure, as presented in the example below.

...
        <aixm:Surface gml:id="S001" srsName="urn:ogc:def:crs:EPSG::4326">
            <gml:patches>
                <gml:PolygonPatch>
                    <gml:exterior>
                        <gml:Ring>
                            <gml:curveMember>
                                <gml:Curve gml:id="CUR001">
                                    <gml:segments>
                                        <gml:CircleByCenterPoint numArc="1">
                                            <gml:pos>51.01555556 2.57138889</gml:pos>
                                            <gml:radius uom="[nmi_i]">12</gml:radius>
                                        </gml:CircleByCenterPoint>
                                    </gml:segments>
                                </gml:Curve>
                            </gml:curveMember>
                </gml:Ring>
                    </gml:exterior>
                </gml:PolygonPatch>
            </gml:patches>
        </aixm:Surface>
...

Note

CircleByCenterPoint should be used only to define a simple circular airspace boundary and it should appear as unique member of a gml:Curve. Otherwise, the orientation of the circle boundary is not well defined.

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