geometryBasic0d1d.xsd Schematron validation The presence of a dimension attribute implies the presence of the srsName attribute. The presence of an axisLabels attribute implies the presence of the srsName attribute. The presence of an uomLabels attribute implies the presence of the srsName attribute. The presence of an uomLabels attribute implies the presence of the axisLabels attribute and vice versa. The presence of a count attribute implies the presence of the dimension attribute. GML is an OGC Standard. Copyright (c) 2001,2005,2010 Open Geospatial Consortium. To obtain additional rights of use, visit http://www.opengeospatial.org/legal/ . This includes not only measures.xsd, but also units.xsd, gmlBase.xsd and basicTypes.xsd. The "_Geometry" element is the abstract head of the substituition group for all geometry elements of GML 3. This includes pre-defined and user-defined geometry elements. Any geometry element must be a direct or indirect extension/restriction of AbstractGeometryType and must be directly or indirectly in the substitution group of "_Geometry". A geometric property can either be any geometry element encapsulated in an element of this type or an XLink reference to a remote geometry element (where remote includes geometry elements located elsewhere in the same document). Note that either the reference or the contained element must be given, but not both or none. This attribute group includes the XLink attributes (see xlinks.xsd). XLink is used in GML to reference remote resources (including those elsewhere in the same document). A simple link element can be constructed by including a specific set of XLink attributes. The XML Linking Language (XLink) is currently a Proposed Recommendation of the World Wide Web Consortium. XLink allows elements to be inserted into XML documents so as to create sophisticated links between resources; such links can be used to reference remote properties. A simple link element can be used to implement pointer functionality, and this functionality has been built into various GML 3 elements by including the gml:AssociationAttributeGroup. A container for an array of geometry elements. The elements are always contained in the array property, referencing geometry elements or arrays of geometry elements is not supported. All geometry elements are derived directly or indirectly from this abstract supertype. A geometry element may have an identifying attribute ("gml:id"), a name (attribute "name") and a description (attribute "description"). It may be associated with a spatial reference system (attribute "srsName"). The following rules shall be adhered: - Every geometry type shall derive from this abstract type. - Every geometry element (i.e. an element of a geometry type) shall be directly or indirectly in the substitution group of _Geometry. This attribute is included for backward compatibility with GML 2 and is deprecated with GML 3. This identifer is superceded by "gml:id" inherited from AbstractGMLType. The attribute "gid" should not be used anymore and may be deleted in future versions of GML without further notice. In general this reference points to a CRS instance of gml:CoordinateReferenceSystemType (see coordinateReferenceSystems.xsd). For well known references it is not required that the CRS description exists at the location the URI points to. If no srsName attribute is given, the CRS must be specified as part of the larger context this geometry element is part of, e.g. a geometric element like point, curve, etc. It is expected that this attribute will be specified at the direct position level only in rare cases. The "srsDimension" is the length of coordinate sequence (the number of entries in the list). This dimension is specified by the coordinate reference system. When the srsName attribute is omitted, this attribute shall be omitted. Ordered list of labels for all the axes of this CRS. The gml:axisAbbrev value should be used for these axis labels, after spaces and forbiddden characters are removed. When the srsName attribute is included, this attribute is optional. When the srsName attribute is omitted, this attribute shall also be omitted. Ordered list of unit of measure (uom) labels for all the axes of this CRS. The value of the string in the gml:catalogSymbol should be used for this uom labels, after spaces and forbiddden characters are removed. When the axisLabels attribute is included, this attribute shall also be included. When the axisLabels attribute is omitted, this attribute shall also be omitted. Optional reference to the CRS used by this geometry, with optional additional information to simplify use when a more complete definition of the CRS is not needed. In general this reference points to a CRS instance of gml:CoordinateReferenceSystemType (see coordinateReferenceSystems.xsd). For well known references it is not required that the CRS description exists at the location the URI points to. If no srsName attribute is given, the CRS must be specified as part of the larger context this geometry element is part of, e.g. a geometric element like point, curve, etc. It is expected that this attribute will be specified at the direct position level only in rare cases. The "srsDimension" is the length of coordinate sequence (the number of entries in the list). This dimension is specified by the coordinate reference system. When the srsName attribute is omitted, this attribute shall be omitted. Optional additional and redundant information for a CRS to simplify use when a more complete definition of the CRS is not needed. This information shall be the same as included in the more complete definition of the CRS, referenced by the srsName attribute. When the srsName attribute is included, either both or neither of the axisLabels and uomLabels attributes shall be included. When the srsName attribute is omitted, both of these attributes shall be omitted. Ordered list of labels for all the axes of this CRS. The gml:axisAbbrev value should be used for these axis labels, after spaces and forbiddden characters are removed. When the srsName attribute is included, this attribute is optional. When the srsName attribute is omitted, this attribute shall also be omitted. Ordered list of unit of measure (uom) labels for all the axes of this CRS. The value of the string in the gml:catalogSymbol should be used for this uom labels, after spaces and forbiddden characters are removed. When the axisLabels attribute is included, this attribute shall also be included. When the axisLabels attribute is omitted, this attribute shall also be omitted. The "_GeometricPrimitive" element is the abstract head of the substituition group for all (pre- and user-defined) geometric primitives. This is the abstract root type of the geometric primitives. A geometric primitive is a geometric object that is not decomposed further into other primitives in the system. All primitives are oriented in the direction implied by the sequence of their coordinate tuples. A property that has a geometric primitive as its value domain can either be an appropriate geometry element encapsulated in an element of this type or an XLink reference to a remote geometry element (where remote includes geometry elements located elsewhere in the same document). Either the reference or the contained element must be given, but neither both nor none. This attribute group includes the XLink attributes (see xlinks.xsd). XLink is used in GML to reference remote resources (including those elsewhere in the same document). A simple link element can be constructed by including a specific set of XLink attributes. The XML Linking Language (XLink) is currently a Proposed Recommendation of the World Wide Web Consortium. XLink allows elements to be inserted into XML documents so as to create sophisticated links between resources; such links can be used to reference remote properties. A simple link element can be used to implement pointer functionality, and this functionality has been built into various GML 3 elements by including the gml:AssociationAttributeGroup. A Point is defined by a single coordinate tuple. GML supports two different ways to specify the direct poisiton of a point. 1. The "pos" element is of type DirectPositionType. Deprecated with GML version 3.1.0 for coordinates with ordinate values that are numbers. Use "pos" instead. The "coordinates" element shall only be used for coordinates with ordinates that require a string representation, e.g. DMS representations. Deprecated with GML version 3.0. Use "pos" instead. The "coord" element is included for backwards compatibility with GML 2. This property element either references a point via the XLink-attributes or contains the point element. pointProperty is the predefined property which can be used by GML Application Schemas whenever a GML Feature has a property with a value that is substitutable for Point. Deprecated with GML version 3.1.0. Use "pointProperty" instead. Included for backwards compatibility with GML 3.0.0. A property that has a point as its value domain can either be an appropriate geometry element encapsulated in an element of this type or an XLink reference to a remote geometry element (where remote includes geometry elements located elsewhere in the same document). Either the reference or the contained element must be given, but neither both nor none. A container for an array of points. The elements are always contained in the array property, referencing geometry elements or arrays of geometry elements is not supported. The "_Curve" element is the abstract head of the substituition group for all (continuous) curve elements. An abstraction of a curve to support the different levels of complexity. The curve can always be viewed as a geometric primitive, i.e. is continuous. This property element either references a curve via the XLink-attributes or contains the curve element. curveProperty is the predefined property which can be used by GML Application Schemas whenever a GML Feature has a property with a value that is substitutable for _Curve. A property that has a curve as its value domain can either be an appropriate geometry element encapsulated in an element of this type or an XLink reference to a remote geometry element (where remote includes geometry elements located elsewhere in the same document). Either the reference or the contained element must be given, but neither both nor none. This attribute group includes the XLink attributes (see xlinks.xsd). XLink is used in GML to reference remote resources (including those elsewhere in the same document). A simple link element can be constructed by including a specific set of XLink attributes. The XML Linking Language (XLink) is currently a Proposed Recommendation of the World Wide Web Consortium. XLink allows elements to be inserted into XML documents so as to create sophisticated links between resources; such links can be used to reference remote properties. A simple link element can be used to implement pointer functionality, and this functionality has been built into various GML 3 elements by including the gml:AssociationAttributeGroup. A container for an array of curves. The elements are always contained in the array property, referencing geometry elements or arrays of geometry elements is not supported. A LineString is a special curve that consists of a single segment with linear interpolation. It is defined by two or more coordinate tuples, with linear interpolation between them. It is backwards compatible with the LineString of GML 2, GM_LineString of ISO 19107 is implemented by LineStringSegment. GML supports two different ways to specify the control points of a line string. 1. A sequence of "pos" (DirectPositionType) or "pointProperty" (PointPropertyType) elements. "pos" elements are control points that are only part of this curve, "pointProperty" elements contain a point that may be referenced from other geometry elements or reference another point defined outside of this curve (reuse of existing points). 2. The "posList" element allows for a compact way to specifiy the coordinates of the control points, if all control points are in the same coordinate reference systems and belong to this curve only. The number of direct positions in the list must be at least two. Deprecated with GML version 3.1.0. Use "pointProperty" instead. Included for backwards compatibility with GML 3.0.0. Deprecated with GML version 3.0. Use "pos" instead. The "coord" element is included for backwards compatibility with GML 2. Deprecated with GML version 3.1.0. Use "posList" instead. DirectPosition instances hold the coordinates for a position within some coordinate reference system (CRS). Since DirectPositions, as data types, will often be included in larger objects (such as geometry elements) that have references to CRS, the "srsName" attribute will in general be missing, if this particular DirectPosition is included in a larger element with such a reference to a CRS. In this case, the CRS is implicitly assumed to take on the value of the containing object's CRS. Optional reference to the CRS used by this geometry, with optional additional information to simplify use when a more complete definition of the CRS is not needed. In general this reference points to a CRS instance of gml:CoordinateReferenceSystemType (see coordinateReferenceSystems.xsd). For well known references it is not required that the CRS description exists at the location the URI points to. If no srsName attribute is given, the CRS must be specified as part of the larger context this geometry element is part of, e.g. a geometric element like point, curve, etc. It is expected that this attribute will be specified at the direct position level only in rare cases. The "srsDimension" is the length of coordinate sequence (the number of entries in the list). This dimension is specified by the coordinate reference system. When the srsName attribute is omitted, this attribute shall be omitted. Ordered list of labels for all the axes of this CRS. The gml:axisAbbrev value should be used for these axis labels, after spaces and forbiddden characters are removed. When the srsName attribute is included, this attribute is optional. When the srsName attribute is omitted, this attribute shall also be omitted. Ordered list of unit of measure (uom) labels for all the axes of this CRS. The value of the string in the gml:catalogSymbol should be used for this uom labels, after spaces and forbiddden characters are removed. When the axisLabels attribute is included, this attribute shall also be included. When the axisLabels attribute is omitted, this attribute shall also be omitted. DirectPositionList instances hold the coordinates for a sequence of direct positions within the same coordinate reference system (CRS). In general this reference points to a CRS instance of gml:CoordinateReferenceSystemType (see coordinateReferenceSystems.xsd). For well known references it is not required that the CRS description exists at the location the URI points to. If no srsName attribute is given, the CRS must be specified as part of the larger context this geometry element is part of, e.g. a geometric element like point, curve, etc. It is expected that this attribute will be specified at the direct position level only in rare cases. The "srsDimension" is the length of coordinate sequence (the number of entries in the list). This dimension is specified by the coordinate reference system. When the srsName attribute is omitted, this attribute shall be omitted. Ordered list of labels for all the axes of this CRS. The gml:axisAbbrev value should be used for these axis labels, after spaces and forbiddden characters are removed. When the srsName attribute is included, this attribute is optional. When the srsName attribute is omitted, this attribute shall also be omitted. Ordered list of unit of measure (uom) labels for all the axes of this CRS. The value of the string in the gml:catalogSymbol should be used for this uom labels, after spaces and forbiddden characters are removed. When the axisLabels attribute is included, this attribute shall also be included. When the axisLabels attribute is omitted, this attribute shall also be omitted. "count" allows to specify the number of direct positions in the list. If the attribute count is present then the attribute srsDimension shall be present, too. Vector instances hold the compoents for a (usually spatial) vector within some coordinate reference system (CRS). Since Vectors will often be included in larger objects that have references to CRS, the "srsName" attribute may be missing. In this case, the CRS is implicitly assumed to take on the value of the containing object's CRS. Note that this content model is the same as DirectPositionType, but is defined separately to reflect the distinct semantics, and to avoid validation problems. SJDC 2004-12-02 A geometric position represented either by a DirectPosition or a Point. A list of geometric positions represented either by a DirectPosition or a Point. Deprecated with GML version 3.1.0. Envelope defines an extent using a pair of positions defining opposite corners in arbitrary dimensions. The first direct position is the "lower corner" (a coordinate position consisting of all the minimal ordinates for each dimension for all points within the envelope), the second one the "upper corner" (a coordinate position consisting of all the maximal ordinates for each dimension for all points within the envelope). deprecated deprecated with GML version 3.0 deprecated Deprecated with GML version 3.1. Use the explicit properties "lowerCorner" and "upperCorner" instead. Deprecated with GML version 3.1.0. Use the explicit properties "lowerCorner" and "upperCorner" instead. Deprecated with GML 3.0 and included for backwards compatibility with GML 2. Use the "pos" element instead. Represents a coordinate tuple in one, two, or three dimensions. Deprecated with GML 3.0 and replaced by DirectPositionType. Deprecated with GML 3.0 and included only for backwards compatibility with GML 2.0. Use "curveProperty" instead. This property element either references a line string via the XLink-attributes or contains the line string element. This type is deprecated with GML 3 and shall not be used. It is included for backwards compatibility with GML 2. Use CurvePropertyType instead. A property that has a line string as its value domain can either be an appropriate geometry element encapsulated in an element of this type or an XLink reference to a remote geometry element (where remote includes geometry elements located elsewhere in the same document). Either the reference or the contained element must be given, but neither both nor none. This attribute group includes the XLink attributes (see xlinks.xsd). XLink is used in GML to reference remote resources (including those elsewhere in the same document). A simple link element can be constructed by including a specific set of XLink attributes. The XML Linking Language (XLink) is currently a Proposed Recommendation of the World Wide Web Consortium. XLink allows elements to be inserted into XML documents so as to create sophisticated links between resources; such links can be used to reference remote properties. A simple link element can be used to implement pointer functionality, and this functionality has been built into various GML 3 elements by including the gml:AssociationAttributeGroup.