Recommendation

Each ICAO data set should be provided together with metadata giving the geographical extent of the data set.
This requirement can be fulfilled in one of three ways:

GeographicDescription; or
GeographicBoundingBox; or
BoundingPolygon.

Geographic Description

Requirement	Reference	DS-META-007
	Element Name	Geographical extent of the data set
	Obligation / Condition	Mandatory. One of the three options must be provided.
	Multiplicity	1..*
ISO 19115 (2003)	Number	349
	Name	geographicIdentifier
	Definition	identifier used to represent a geographic area
	XPath	gmd:MD_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:geographicElement/gmd:EX_GeographicDescription/gmd:MD_Identifier/gmd:code/gco:CharacterString
	Data type	CharacterString
	Domain	Free Text
	Example	Belgium and Luxembourg
Implementing Instructions		-

Example

<gmd:MD_Metadata>
...
 <gmd:identificationInfo>
  <gmd:MD_DataIdentification>
   <gmd:extent>
    <gmd:EX_Extent>
     <gmd:geographicElement>
      <gmd:EX_GeographicDescription>
       <gmd:geographicIdentifier>
        <gmd:MD_Identifier>
         <gmd:code><gco:CharacterString>Belgium and Luxembourg</gco:CharacterString></gmd:code>
        </gmd:MD_Identifier>
       </gmd:geographicIdentifier>
      </gmd:EX_GeographicDescription>
     </gmd:geographicElement>
    </gmd:EX_Extent>
   </gmd:extent>
  </gmd:MD_DataIdentification>
 </gmd:identificationInfo>
...
</gmd:MD_Metadata>

Geographic Bounding Box

Requirement	Reference	DS-META-007
	Element Name	Geographical extent of the data set
	Obligation / Condition	Mandatory. One of the three options must be provided.
	Multiplicity	1..*
ISO 19115	Number	344
	Name	westBoundLongitude
	Definition	Western-most coordinate of the limit of the dataset extent, expressed in longitude in decimal degrees (positive east)
	XPath	gmd:MD_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:geographicElement/gmd:EX_GeographicBoundingBox/gmd:westBoundLongitude/gco:Decimal
	Data type	Decimal
	Domain	-180.00 <= West Bounding Longitude Value <= 180.00
	Example	3.93
ISO 19115	Number	345
	Name	eastBoundLongitude
	Definition	Eastern-most coordinate of the limit of the dataset extent, expressed in longitude in decimal degrees (positive east)
	XPath	gmd:MD_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:geographicElement/gmd:EX_GeographicBoundingBox/gmd:eastBoundLongitude/gco:Decimal
	Data type	Decimal
	Domain	-180.00 <= East Bounding Longitude Value <= 180.00
	Example	7.57
ISO 19115	Number	346
	Name	southBoundLatitude
	Definition	Southern-most coordinate of the limit of the dataset extent, expressed in latitude in decimal degrees (positive north)
	XPath	gmd:MD_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:geographicElement/gmd:EX_GeographicBoundingBox/gmd:southBoundLatitude/gco:Decimal
	Data type	Decimal
	Domain	-90.00 <= South Bounding Latitude Value <= North Bounding Latitude Value
	Example	52.10
ISO 19115	Number	347
	Name	northBoundLatitude
	Definition	Northern-most coordinate of the limit of the dataset extent, expressed in latitude in decimal degrees (positive north)
	XPath	gmd:MD_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:geographicElement/gmd:EX_GeographicBoundingBox/gmd:northBoundLatitude/gco:Decimal
	Data type	Decimal
	Domain	South Bounding Latitude Value <= North Bounding Latitude Value <= 90.00
	Example	54.10
Implementing Instructions		-

Example

<gmd:MD_Metadata>
...
 <gmd:identificationInfo>
  <gmd:MD_DataIdentification>
   <gmd:extent>
    <gmd:EX_Extent>
     <gmd:geographicElement>
      <gmd:EX_GeographicBoundingBox>
       <gmd:westBoundLongitude><gco:Decimal>3.93</gco:Decimal></gmd:westBoundLongitude>
       <gmd:eastBoundLongitude><gco:Decimal>7.57</gco:Decimal></gmd:eastBoundLongitude>
       <gmd:southBoundLatitude><gco:Decimal>52.10</gco:Decimal></gmd:southBoundLatitude>
       <gmd:northBoundLatitude><gco:Decimal>54.10</gco:Decimal></gmd:northBoundLatitude>
      </gmd:EX_GeographicBoundingBox>
     </gmd:geographicElement>
    </gmd:EX_Extent>
   </gmd:extent>
  </gmd:MD_DataIdentification>
 </gmd:identificationInfo>
...
</gmd:MD_Metadata>

BoundingPolygon

Requirement	Reference	DS-META-007
	Element Name	Geographical extent of the data set
	Obligation / Condition	Mandatory. One of the three options must be provided.
	Multiplicity	1..*
ISO 19115 (2003)	Number	342
	Name	polygon
	Definition	set of points defining the bounding polygon
	XPath	gmd:MetaData/gmd:identificationInfo/gmd:DataIdentification/gmd:extent/gmd:EX_Extent/gmd:geographicElement/gmd:EX_BoundingPolygon/gmd:polygon
	Data type	Class
	Domain	GM_Object
	Example	30 30 30 40 60 40 60 30
Implementing Instructions		-

Example

<gmd:MD_Metadata>
...
 <gmd:identificationInfo>
  <gmd:DataIdentification>
   <gmd:extent>
    <gmd:geographicElement>
     <gmd:EX_BoundingPolygon>
      <gmd:polygon> - various options exist for completing the polygon. Please refer to the ¿Guidance and Profile of GML for use with Aviation Data¿ [5].</gmd:polygon>
     </gmd:EX_BoundingPolygon>
    </gmd:geographicElement>
   </gmd:extent>
  </gmd:DataIdentification>
 <gmd:identificationInfo>
...
</gmd:MD_Metadata>

Requirement 7_ Geographical extent of the data set

Geographic Description

Geographic Bounding Box

BoundingPolygon