Data formats

The AddressBase Premium Islands product is distributed as comma-separated value (CSV), Geography Markup Language (GML) version 3.2.1 or GeoPackage (GPKG) formats. The CSV and GML formats can be supplied as a full supply or a change-only update (COU); the GPKG format is available as a full supply only.

CSV

The CSV supply of AddressBase Premium means:

• There will be one record per line in each file.

• Fields will be separated by commas.

• String fields will be delimited by double quotes.

• No comma will be placed at the end of each row in the file.

• Records will be terminated by Carriage Return / Line Feed.

• Double quotes inside strings will be escaped by doubling.

Where a field has no value in a record, two commas will be placed together in the record (one for the end of the previous field and one for the end of the null field). Where the null field is a text field double quotes will be included between the two commas, for example - “”.

AddressBase Premium CSV data will be transferred using Unicode encoded in UTF-8. Unicode includes all the characters in ISO-8859-14 (Welsh characters). Some accented characters are encoded differently.

The transfer will normally be in a single file, but the data can be split into multiple files using volume numbers. AddressBase Premium records are provided within continuous files cut at approximately 1 million lines as referred to above.

Street and Street Descriptor records are provided together and then a new file is started independent of count for the additional record types.

This means different record types, for example, BLPU and LPIs (see AddressBase Premium Island structure) can be found in the same CSV file.

The record types are provided in the following order:

• Street (Type 11)

• Street Descriptor (Type 15) – a new file is started after the last Street Descriptor record for your supply is reached

• BLPU (Type 21)

• LPI (Type 24)

• Delivery Point Address (Type 28)

• Organisation (Type 31)

• Classification (Type 32)

• Application Cross Reference (Type 23)

GML

The GML Encoding standard is an Extensible Markup Language (XML) grammar for expressing geographical features. XML schemas are used to define and validate the format and content of GML. The XML specifications that GML is based on are available from the World Wide Web Consortium (W3C) website: http://www.w3.org. More information can be found in the Open Geospatial Consortium (OGC) document, Geography Markup Language v3.2.1.

The GML 3.2.1 specification provides a set of schemas that define the GML feature constructs and geometric types. These are designed to be used as a basis for building application-specific schemas, which define the data content.

A GML document is described using an XML schema. The AddressBase Premium Islands schema document (addressbasepremium.xsd) defines the features in AddressBase Premium GML and is available on the Ordnance Survey website at: https://www.ordnancesurvey.co.uk/xml/products/AddressBasePremium.xml. It imports the GML 3.2.1 schemas which rely on XML, as defined by W3C at: http://www.w3.org/XML/1998/namespace.html.

The application schema uses the following XML namespaces:

Prefix	Namespace Identifier	Definition Available at
gml	http://www.opengis.net/gml	http://schemas.opengis.net/gml/3.2.1/gml.xsd
xsi	http://www.w3.org/2001/XMLSchema http://www.w3.org/2001/XMLSchema-instance	Built into XML – http://www.w3.org/TR/xmlschema-1/
xlink	Xlink – http://www.w3.org/1999/xlink	http://www.w3.org/1999/xlink.xsd

Information about Unicode and UTF-8, the character encoding we have chosen, is available on the Unicode Consortium website.

Features

Each feature within the AddressBaseSupplySet:FeatureCollection is encapsulated in the following member element according to its feature type:

BLPU

• Feature Type: BasicLandPropertyUnit

• Member Element: <abpr:basicLandPropertyUnitMember>

The UPRN of the feature is provided in the XML attribute of the gml:id

<abpr: basicLandPropertyUnitMember> 
<abpr: BasicLandPropertyUnit gml:id=”uk.geoplace.uprn.1000011535314”> 
……………….. 
</abpr:BasicLandPropertyUnit> 
</abpr: basicLandPropertyUnitMember> 

Street

• Feature Type: Street

• Member Element: <abpr:streetMember>

The USRN of the feature is provided in the XML attribute of the gml:id

<abpr: streetMember> 
<abpr:Street gml:id=”uk.geoplace.usrn.14200295”> 
……………….. 
</abpr:Street> 
</abpr: streetMember>

See Example records > GML for specific GML examples.

Envelope

In the GML supply, you can determine the extent of your supply by the <gml: Envelope>. Because Latitude and Longitude are the mandatory coordinates in AddressBase Premium Islands the envelope uses these coordinates. For example:

<gml:boundedBy> 
<gml:Envelope srsName="urn:ogc:def:crs:EPSG::4258"> 
<gml:lowerCorner>48.40 -8.30</gml:lowerCorner> 
<gml:upperCorner>55.50 -1.80</gml:upperCorner> 
</gml:Envelope> 
</gml:boundedBy> 

GPKG

GPKG is an open, standards-based data format as defined by the Open Geospatial Consortium (OGC). It is designed to be a lightweight format that can contain large amounts of varied and complex data in a single, easy to distribute and ready to use file. Please be advised that older versions of GIS software may need updating before being able to display and interact with GPKG files.

GPKG offers the following benefits:

• The single file is easy to transfer and offers the end-user a rich experience.

• Attribute names are not limited in length, making it user friendly.

• The file size limit is very large at 140 TB1, so lots of data can be easily accommodated.

• It supports raster, vector and database formats, making it a highly versatile solution.

• It is an OGC Standard.

• In most cases, it is a plug-in-and-play format.