> For the complete documentation index, see [llms.txt](https://docs.os.uk/os-downloads/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.os.uk/os-downloads/products/land-and-terrain-portfolio/os-terrain-5/os-terrain-5-technical-specification/metadata.md).

# Metadata

The XML metadata for the terrain products follows the GEMINI metadata standard, which Ordnance Survey has committed to for the UK Location Programme and INSPIRE.

OS Terrain 5 will also have metadata in this form, on a per-tile basis.

The XML metadata contains comments to clarify the meaning of the XML tags used in the file.

## Product identification table <a href="#id-4.1-product-identification-table" id="id-4.1-product-identification-table"></a>

| Name                         | Description                                                                                                                                                                    | Examples                                                                                                                                                                                                                                                                                                                                                                 |
| ---------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| Product name                 | OS Terrain 5                                                                                                                                                                   | gmd:MD\_DataIdentification/gmd:citation/gmd:CI\_C itation/gmd:**collectiveTitle**/gco:CharacterString                                                                                                                                                                                                                                                                    |
| Spatial representation       | The structure of the data, either grid (DTM) or vector (contours).                                                                                                             | gmd:MD\_DataIdentification/gmd:spatialRepresent ationType/gmd:**MD\_SpatialRepresentationType Code**                                                                                                                                                                                                                                                                     |
| Tile reference               | 5km National Grid tile reference.                                                                                                                                              | gmd:MD\_DataIdentification/gmd:citation/gmd:CI\_ Citation/gmd:**title**/gco:CharacterString                                                                                                                                                                                                                                                                              |
| Topic category               | INSPIRE theme: elevation.                                                                                                                                                      | gmd:MD\_DataIdentification/gmd:topicCategory/gm d:**MD\_TopicCategoryCode**                                                                                                                                                                                                                                                                                              |
| Coordinate reference systems | <p>The projected coordinate reference system – British National Grid – and the vertical reference system –</p><p><a href="https://epsg.io/5701">Ordnance Datum Newlyn</a>.</p> | <p>gmd:MD\_ReferenceSystem/gmd:referenceSystemIden tifier/gmd:RS\_Identifier/gmd:code/gmx:Anchor xlink:href="urn:ogc:def:crs:EPSG::27700"/<strong>Britishv National Grid</strong></p><p>gmd:MD\_ReferenceSystem/gmd:referenceSystemIden tifier/gmd:RS\_Identifier/gmd:code/gmx:Anchor xlink:href="urn:ogc:def:crs:EPSG::5701"/<strong>Ordnance Datum Newlyn</strong></p> |

## Change history table <a href="#id-4.2-change-history-table" id="id-4.2-change-history-table"></a>

| Name              | Description                                                                                                                                                                                                                                                                                                                | Examples                                                                                                                                                                                 |
| ----------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Flying date(s)    | <p>The date that the area was flown by Ordnance Survey for revision. To accommodate multiple flying dates within the tile, two values will be recorded: earliest flying date then latest flying date present.</p><p>Both dates can be identical.</p><p>For Profile content the Date Flown will be recorded as \<null>.</p> | <p>gmd:MD\_DataIdentification/gmd:extent/gmd:EX\_Ex tent/gmd:temporalElement/gmd:EX\_TemporalExtent</p><p>/gmd:extent/gml:TimePeriod</p><p>/gml:beginPosition</p><p>/gml:endPosition</p> |
| Processing date   | The date the tile was created by Ordnance Survey, not the date of the real-world change or survey.                                                                                                                                                                                                                         | gmd:MD\_DataIdentification/gmd:citation/gmd:CI\_C itation/gmd:date/gmd:CI\_Date/gmd:date/gco:Date                                                                                        |
| Version number    | An incrementing number to indicate the number of times the tile has been published.                                                                                                                                                                                                                                        | gmd:MD\_DataIdentification/gmd:citation/gmd:CI\_ Citation/gmd:edition/gco:CharacterString                                                                                                |
| Reason for change | This provides information about the update of the data and whether it is creation (new) or a revision (modified / verified) which is described in the metadata by using lineage below.                                                                                                                                     | gmd:MD\_DataIdentification/gmd:citation/gmd:CI\_ Citation/gmd:date/gmd:CI\_Date/gmd:dateType/ gmd:CI\_DateTypeCode                                                                       |
| Lineage           | Text to describe the status of the tile, either: ‘created from new imagery’, ‘some parts revised from new imagery’, ‘new imagery examined and no change’.                                                                                                                                                                  | gmd:DQ\_DataQuality/gmd:lineage/gmd:LI\_Lineage/ gmd:statement/gco:CharacterString                                                                                                       |

## Metadata viewing stylesheet <a href="#id-4.3-metadata-viewing-stylesheet" id="id-4.3-metadata-viewing-stylesheet"></a>

To make the XML easier to read, an XSLT viewing style sheet is provided (OSTerrainMetadataViewingStylesheet.xsl), which converts the XML to HTML for ease of viewing in a web browser. Some browsers and other software will read this automatically if the user is connected to the Internet, as its address is referenced in the metadata but it can also be located on the Ordnance Survey website: <http://www.ordnancesurvey.co.uk/xml/stylesheet/OSTerrainMetadataViewingStylesheet.xsl>.

### Metadata XML file example <a href="#id-4.3.1-metadata-xml-file-example" id="id-4.3.1-metadata-xml-file-example"></a>

This is a section of the XML file in its native format with the location of the style sheet highlighted. It can be read like this when opened in an XML viewer or basic file reader.

```xml
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="
http://www.ordnancesurvey.co.uk/xml/stylesheet/OSTerrainMetadataViewingStylesheet.xsl
"?>
<gmd:MD_Metadata xmlns:gmd
="http://www.isotc211.org/2005/gmd"
 
xmlns:gml="http://www.opengis.net/gml/3.2"
 
xmlns:xsi="http://www.w3.org/2001/XMLSchema
-instance" 
xmlns:gmx="http://www.isotc211.org/2005/gmx" 

xmlns:gco="http://www.isotc211.org/2005/gco"
 
xmlns:xlink="http://www.w3.org/19
99/xlink" 
xsi:schemaLocation="http://www.isotc211.org/2005/gmx
 
http://eden.ign.fr/xsd/isotc211/isofull/20090316/gmx/gmx.xsd"><!
-- Unique identifier, required if this record is being used in a metadata management system -->
<gmd:fileIdentifier>
<gco:CharacterString>OSTerrain5.NT23NE</gco:CharacterString>
</gmd:fileIdentifier>
<gmd:contact gco:nilReason="missing"></gmd:contact>
<gmd:dateStamp>
<gco:DateTime>2013-01-08T03:22:25</gco:DateTime>
</gmd:dateStamp><!-- Projected Coordinate Reference System -->
<gmd:referenceSystemInfo>
<gmd:MD_ReferenceSystem>
<gmd:referenceSystemIdentifier>
<gmd:RS_Identifier>
<gmd:code>
<gmx:Anchor xlink:href="urn:ogc:def:crs:EPSG::27700">British National Grid</gmx:Anchor>
```

### Example of the metadata XML file referencing the XSLT viewing stylesheet <a href="#id-4.3.2-example-of-the-metadata-xml-file-r" id="id-4.3.2-example-of-the-metadata-xml-file-r"></a>

This is the same section of the metadata file above when viewed directly by clicking on the file, utilising the style sheet.

**OS Terrain Tile Metadata Product identification:**

Product name: [OS Terrain 5](https://www.ordnancesurvey.co.uk/xml/products/OSTerrain5Grid.xml)

Spatial representation: Grid

Tile reference: NT23NE

Topic category: Elevation Coordinate reference systems: British National Grid

#### Esri grid styling – asc.aux.xml file <a href="#id-4.3.3-esri-grid-styling-asc.aux.xml-fi" id="id-4.3.3-esri-grid-styling-asc.aux.xml-fi"></a>

This XML file contains min, max, mean, and standard deviation height values for the product, in a format defined by Esri. The same values are supplied for every tile. These height statistics are provided to allow the user to apply colour ramps, such that adjacent tiles are styled consistently.

This feature can be disabled by moving the asc.aux.xml file from each downloaded zip file, or by adjusting the parameters of the minimum and maximum heights in a GIS if desired.


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