DS-META-007 - Geographical extent of the data set

Owned by WILSON Scott
Last updated: 2022 Sept 12

Rule

Each ICAO obstacle data set shall be provided together with metadata giving the geographical extent of the data set.

Recommendation

Each ICAO data set, other than obstacle data sets, should be provided together with metadata giving the geographical extent of the data set.


This requirement is fulfilled by including a geographic description (GeographicDescription) as a clear, textual description of the data set's geographical extent.


Best practice

The inclusion of a bounding box (GeographicBoundingBox) or a polygon (BoundingPolygon) is a good practice in the GIS world. They are useful for applications that represent the data graphically, to set the initial window size. They are also facilitate the evaluation of the geographical coverage of a data set without having to parse and decode the full data set.

Geographic Description

Requirement




Reference

DS-META-007

Element Name

Geographical extent of the data set

Obligation / Condition

Mandatory for obstacle data sets. Optional for other ICAO data sets. If provided:

  • GeographicDescription is mandatory.
  • Either GeographicBoundingBox or BoundingPolygon is recommended.

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:geographicIdentifier/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 for obstacle data sets. Optional for other ICAO data sets. If provided:

  • GeographicDescription is mandatory.
  • Either GeographicBoundingBox or BoundingPolygon is recommended.

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 for obstacle data sets. Optional for other ICAO data sets. If provided:

  • GeographicDescription is mandatory.
  • Either GeographicBoundingBox or BoundingPolygon is recommended.

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".</gmd:polygon>
     </gmd:EX_BoundingPolygon>
    </gmd:geographicElement>
   </gmd:extent>
  </gmd:DataIdentification>
 <gmd:identificationInfo>
...
</gmd:MD_Metadata>