OS Open Map – Local (OML) is an open dataset of detailed, street-level mapping of Great Britain. OML provides one of the most detailed generalised open mapping products available and is designed to provide contextual mapping for your applications or web pages. It offers users a clear contextual view of the world whilst also enabling the undertaking of analytical activities.

OS OML can support a wide range of customer applications that utilise geographic information. The product is ideal for providing backdrop mapping on websites and displaying business locations on small-scale 'street level' maps.

How to get this product

Access to OS OpenData is free through the OS Data Hub.

Visualise OS OpenMap – Local data online

OS OpenMap – Local (OML) is the most detailed ‘street level’ open mapping product available and is designed to provide contextual mapping for your applications or web pages. It offers customers and OS Partners a clear contextual view of the world, whilst also enabling the undertaking of analytical activities.

In the example below, OS OML has been used as backdrop mapping to contextualise and provide a clear visual representation of a heat map for estimated house prices in an area:

OS OML data is available as either pre-styled static images (raster) or interactive vectorised features in a selection of pre-defined or customisable styles.

OS OML contains functional sites, greenspace, important buildings and Department for Transport (DfT) numbers in order to facilitate alignment with other OS products. When using OS OML for contextualised mapping, the nominal viewing scale is 1:10 000, with a recommended viewing scale range of 1:3 000 to 1:20 000.

Product highlights

The key features of the OS OML product are as follows:

• The vector data can be used for contextual mapping purposes and as a basemap with other third-party information.

• A full Great Britain set of data is available in Geography Markup Language (GML) v.3.2.1, ESRI shapefile, GeoPackage and GeoTIFF raster tiles.

• Road classifications are provided alongside comprehensive coverage of road names and numbers, in alignment with other OS products.

• The product contains important buildings, functional sites and greenspace.

• Generalised building geometries are derived from OS MasterMap large-scale data.

• Vector data map styling is highly customisable to suit your needs; premade stylesheets are also available for Ordnance Survey’s traditional styles.

• The product is updated twice a year.

• It is an OpenData product and is thus provided free at the point of use as a download through the OS Data Hub.

All current commonly used versions of MapInfo Professional are able to open ESRI shapefiles without direct translation. However, for ease of use within MapInfo, it is recommended that users use the universal translator within MapInfo to convert the shapefile supply to MapInfo .TAB files prior to loading the data. This will be described in the procedures for loading the data.

Loading and Displaying Shapefile Supply

In MapInfo Professional, start universal translator from the ‘Tools’ menu.

Select the translate button at the top left hand side of the dialog box.

In the next box, the user will need to select the translation parameters required. These will include the format of the files being translated, the format to which the data is being translated and the location of the data.

Once selected, click ‘OK’. The translation will then run.

A message box will appear when the process in complete. The user will now have a MapInfo .TAB file for the selected layer of OS OpenMap-Local. This procedure will have to be repeated for all of the layers within OS OpenMap-Local which are required.

To load the created MapInfo .TAB files into MapInfo Professional simply click ‘File – Open’ and navigate to where the files reside. Select the file to be opened. Select ‘new mapper’ from the drop-down menu and click ‘OK’. For successive layers (if loading one layer at a time) select ‘current mapper’ as some of the data is already loaded. A point to note is that MapInfo Professional will open the data un-styled. The screenshot below shows the TQ Buildings and roads layers loaded.

Styling the data

MapInfo Professional, unlike many other GI applications, is better styled at translation stage because the .TAB format used by MapInfo can retain all of the styling information applied in the translation process – it does not use separate styling files to apply a style to the data. OS OpenMap-Local at the current time is not supplied in MapInfo .TAB format. Therefore, there is no Ordnance Survey published styling information for use in MapInfo Professional at the present time. It is however possible to style the data manually in MapInfo and achieve a pleasing result.

To add a style to a layer which has been loaded, open up the layer control window and then select the style override box;

Click the button and a new region style window will appear. It will then be necessary to select a colour for both the fill and the border for the layer to be styled. When the box containing a number of basic colours appears, select the very south east box (with the …. pattern in it) and the next window pops up which will allow a specific RGB value to be entered.

Select a suitable RGB layer for the foreground and then for the border. The selected style will now appear for the layer. Repeat this procedure for all of the other layers in OS OpenMap-Local.

For the layers within OS OpenMap-Local which require different styles to be applied to different attributes within the layer, it is necessary within MapInfo to select out the different attributes using a query. Once the attribute is selected, it will be possible to style on that attribute, either within the original .TAB file or by creating a new subset .TAB file. This second option will be described here as it allows the end user to have more flexibility in terms of layer ordering and allows different subsets of OS OpenMap - Local to be loaded and used for different requirements.

The example below shows a few of the elements of the ‘roads’ layer have already been styled;

In the example following, another element of the OS OpenMap-Local ‘roads’ layer will be styled by creating a new .TAB file for the ‘Primary Roads Collapsed Dual Carriageway’ element of the TQ_Roads layer.

Firstly, from the main menu, select ‘Query’ and ‘SQL Select’.

In the window that follows enter into the relevant boxes the information required to pull out the primary roads, collapsed dual carriageway element of the roads layer;

When creating the new table be sure that the table name being assigned does not contain spaces. Click ‘OK’. MapInfo will now create a new .TAB file query for that element of the data. To save out this query as a .TAB file select from the main menu, ‘File, Save Copy As..’ and then select the name of the table.

Then click the ‘Save As’ button.

At the next window, select the location for the .TAB file and then click ‘OK’. Click ‘File, open’ at the main menu and select the newly created table.

Once selected, click ‘OK’. The new table will appear in the layer control window.

The user can now style this table with an appropriate style as required. A result of this may look like the following depending upon what style is selected.

This procedure will have to be repeated for other elements of the roads layer as required. In OS OpenMap-Local, the functional sites, roundabouts and roads layers will require this approach. All of the other layer elements can be styled on a simple individual basis.

Merging multiple .TAB files in MapInfo Professional

In MapInfo it is possible to merge the elements of two .TAB files together into one new table using the ‘append’ function. This only works for data tables of the same type and will only work for two .TAB files at a time. Please note that the file into which the new data is appended will need to be saved as a new table at the end of the process. This append process will have to be repeated for all elements of the OS OpenMap-Local data if two areas are required.

If the user wishes to merge elements of more than two .TAB files together at the same time, for example, if there was a requirement to combine the elements of TQ, SU and TL together; the user would have to use another solution. A number of custom built script files have been written for MapInfo and are available on the internet. An alternative would be to use the freely available open-source GIS QGIS to merge the shapefiles together before creating the .TAB files in MapInfo. The user should be aware that these merged tables will contain duplicate features.

The example shows the result of appending the SU_Roads element of OS OpenMap-Local into the TQ_Roads table. The ‘TQ_Roads_merged’ table should be saved as a copy of the TQ_Roads table to keep the merged data.

Deleting Duplicate entries from the merged table

There are several ways of doing this in MapInfo Professional. One of the ways to use SQL queries is described in the MapInfo knowledge base article which can be found here:

Coordinate reference system

The vector product formats allow for the use of a variety of coordinate reference systems. At present, only British National Grid (BNG) is used in OS OML vector and raster data. The BNG spatial reference system uses the OSGB36 geodetic datum and a single Transverse Mercator projection for the whole of Great Britain. Positions on this projection are described using easting and northing coordinates in units of metres.

Currency

OS OML is derived from the latest versions of our OS MasterMap large-scale data and is refreshed every six months. More information about the OS MasterMap revision policy is available on the OS website.

Completeness

During production, numerous checks are undertaken to ensure that the data supplied to customers is both accurate and complete. During digital manipulation and data creation, all data sources are checked for conformance to specification.

These quality checks take the form of:

• Visual checks by operators.

• Data testing against the product specification.

• Data testing on a selection of tiles from the full national set.

Generalisation

Geometry within OS OML has been generalised from Ordnance Survey large‑scale data. Map generalisation is the process of reducing the scale and complexity of map detail while maintaining the important elements and characteristics of the geometry.

Map generalisation comprises the following processes:

• Selection/omission: Some features that appear at larger scales are not selected at the smaller scales. For example, in the public amenities layer, individual features in close proximity can be grouped to a single point.

• Simplification: Simplification can take a number of forms in OS OML, including line simplification. For example, in the vector product, a stream can have many curves; these curves are represented by a number of data points which are filtered and will maintain the feature's shape.

• Exaggeration: This is the process whereby features that are small but are considered too important to a particular landscape to be omitted are enlarged. For example, isolated rural buildings are often enlarged to a minimum size rather than being omitted.

• Aggregation: Aggregation is the combining of a number of small features to make a larger one, such as buildings.

• Symbolisation: Features that are shown in detail in OS VectorMap Local may be collapsed to points within OS OML, which can then be symbolised if required. For example, railway stations and airports are depicted as point symbols.

• Displacement: This is the movement of the representation of a feature away from its ground position in order to maintain its prominence. There is very little displacement in OS OML, but in certain circumstances, some features may be moved away from adjacent detail if their representation would otherwise be lost.

Edgematching

In the vector product, features that cross tile edges are included in both tiles, represented as 'hairy' tiles. This facilitates the creation of a seamless dataset and avoids the creation of invalid geometries from arbitrarily cutting features along the tile border. All features have unique identifiers which can be used to remove the duplicated features across tile edges when stitching the tiles together. This supports the greater use of the data in large-scale analytical applications.

OS OpenMap – Local (OML) is the most detailed ‘street level’ open mapping product available and is designed to provide contextual mapping for your applications or web pages. It offers customers and OS Partners a clear contextual view of the world, whilst also enabling the undertaking of analytical activities.

OS OML data is available as either pre-styled static images (raster) or interactive vectorised features in a selection of pre-defined or customisable styles.

The vectorised format of the product consists of multiple layers of feature information which can be individually interrogated, displayed and styled to suit your needs. Stylesheets are available for this product in GitHub.

The rasterised layers provide pre-defined static contextual mapping that is designed to allow customers to overlay their own data clearly. More information on styling can be found in the Getting Started Guide.

OS OML contains functional sites, greenspace, important buildings and Department for Transport (DfT) numbers in order to facilitate alignment with other OS products. When using OS OML for contextualised mapping, the nominal viewing scale is 1:10 000, with a recommended viewing scale range of 1:3 000 to 1:20 000.

Index

• Data structure

• Feature types

• Code lists

This section describes the three features available in OS OpenMap – Local. The attributes associated with these feature types are listed below along with a brief description of their data properties.

Feature type Attribute information

Name and Definition

The name of the attribute and what it is describing.

Attribute Type

The nature of the attribute, for example, a numeric value or a code list value.

Length

Values are given here to indicate the maximum length that you will find in the data, to aid in developing applications. Length is not constrained in the GML (Geography Markup Language).

Multiplicity

Describes how many times this element is expected to be populated in the data. An attribute may be optional or mandatory, and it may have multiple occurrences. For example:

• ‘1’ – there must be a value.

• ‘2’ – there must be two values.

• ‘n’ – there may be one or more values.

• ‘0’ – population is optional.

These values may be used in combination.

Association

An association identifies the relationship between features. The relationships are by reference only and the value will be the identifier of the referenced feature.

Handling OS Open Map – Local Data

From the end of October 2016, OS OpenMap – Local will be available as both a raster version and a vector version as previously. This getting started guide illustrates how to load both raster and vector versions of the product into several GI applications.

Downloaded data

OS OpenMap-Local raster data can be downloaded from the OS OpenData website in GeoTIFF format. This format does not require the use of geo-referencing files in the loading process. The data will be available in 100km² grid zip files, aligned to National Grid letters.

OS OpenMap-Local vector data can be downloaded from the OS OpenData website in either ESRI Shapefile format or in .GML format version 3.2.1. It is available as 100km² tiles which are aligned to the 100km national gird letters, for example, TQ. The data can also be downloaded as a national set in ESRI shapefile format only. The data will not be available for supply on hard media as in the case of some other OS OpenData products.

• ESRI shapefile supply.

The data is supplied in a .zip archive containing a parent folder with two sub folders entitled DATA and DOC. All of the component shapefiles are contained within the DATA folder. The data is supplied as ‘hairy tiles’ in that no feature is broken at the tile edge, but is included across the tile boundary if it extends into an adjacent tile. A data holding comprising of more than one 100km² tile will contain duplicate features which may need to be removed depending upon the user requirement.

• GML supply.

The data is supplied in a .zip archive containing a parent folder with two sub-folders entitled DATA and DOC. The data is supplied in the DATA folder as one .GML file covering the whole area. The data is supplied as ‘hairy tiles’ in that no feature is broken at the tile edge, but is included across the tile boundary if it extends into an adjacent tile. As with the shapefile supply, a data holding comprising of more than one 100km² tile will contain duplicate features which may need to be removed depending on the user's requirement.

Media

There are currently no plans to make this product available on hard media supply.

Index

The OS OpenMap – Local Getting Started guide is broken down into the following topics:

• Loading raster data

• Loading vector data

• Loading and displaying GML data

• POSTGIS

• Loading and Displaying Shapefile Supply

• Viewing the data in QGIS

• Using shapefiles in PostGIS

• Using MapInfo Professional

Road tunnels are represented as approximate centrelines of the road that runs through the tunnel.

RoadTunnel attributes

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Line representing the alignment of the road tunnel.

• Type: GM_Curve

• Multiplicity: [1]

Available formats for the product

OS OML is available in the following formats:

• Vector: GML (Geography Markup Language) v.3.2.1 Simple Features and schema, which is zipped as a single file using gzip.

• Vector: ESRI shapefile, with each tile dataset zipped using gzip.

• Vector: GeoPackage, with a single zipped file for a national set (Great Britain).

• Raster: GeoTIFF, compressed using LZW (Lempel-Ziv-Welch), is a TIFF file which has geographic (or cartographic) data embedded as tags within it. The geographic data can then be used to position the image in the correct location and with precise geometry on the screen of a geographic information display.

Coverage and file sizes

• Coverage is Great Britain (i.e. England, Wales and Scotland).

GML

• 55 tiles, each covering 100km x 100km, comprise the national set (Great Britain)

• Each tile comprises up to 71 feature codes

• Features that cross the tile edge are not split and are therefore duplicated within adjacent tiles (as explained in the edgematching section)

• Tile sizes range from 10KB to approximately 200MB zipped

• The file size of the national set (Great Britain) is 2.4GB zipped

ESRI shapefile

• 55 tiles, each covering 100km x 100km, comprise the national set (Great Britain)

• Each tile comprises a set of up to 20 shapefiles

• Each shapefile holds a single feature type

• Features that cross the tile edge are not split and are therefore duplicated within adjacent tiles (as explained in the edgematching section)

• Tile sizes range from <17KB to approximately 181MB zipped

• The data is not encrypted

• The file size of the national set (Great Britain) is 2.4GB zipped

GeoPackage

• Only available as a national set (Great Britain)

• Single file contains all the feature types

• The data is not encrypted

• The file size of the national set (Great Britain) is 3.8GB zipped

Colour raster GeoTIFF

• 10 588 tiles, each covering 5km x 5km, comprise the national set (Great Britain)

• GeoTIFF and compressed using LZW compression

• Tile sizes range from 6KB to approximately 921MB zipped

• The data is not encrypted

• The file size of the national set (Great Britain) is 15GB zipped

Product update schedule

OS OML is supplied to customers bi-annually in April and October, incorporating any updates made by the revision programme.

Product supply mechanism

OS OML is supplied as an online download, which is available with no registration required. Data can be downloaded in various formats from the OS Data Hub.

A road is defined as a metalled way for vehicles. A vehicle is defined as one with wheels on both sides of its body. Metalling is defined as any artificial (man-made) surface including areas of asphalt, concrete and gravel. Roads that form part of the public network and driveways to private properties that are over 100m in length are captured. Dual carriageways are represented by centrelines when the two carriageways are closer than 32.5m, roundabouts are represented by points when smaller than 450m², dead ends are removed when shorter than 36m, and roads are simplified with a 4m tolerance.

Road attributes

classification

The classification of the Road. The valid values are defined in the RoadClassification Code List

• Type: RoadClassificationType

• Length: 45

• Multiplicity: [1]

distinctiveName

The name of the road. When a road is dual named, the Welsh or Gaelic name is presented first, followed by a space, a forward slash, a space and then the English name.

• Type: CharacterString

• Length: 100

• Multiplicity: [0..1]

drawLevel

The drawLevel value of the Road, used for cartographic styling. The valid values are defined in the DrawLevelValue Code List.

• Type: DrawLevelValue

• Length: 1

• Multiplicity: [1]

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Line representing the alignment of the road.

• Type: GM_Curve

• Multiplicity: [1]

override

The override value of the Road used for cartographic styling. The valid values are defined in the OverrideValue Code List.

• Type: OverrideValue

• Length: 1

• Multiplicity: [1]

roadNumber

For Roads with RoadClassification of Motorway, Primary Road, A Road and B Road, this is the number of the road defined by the Department for Transport.

• Type: CharacterString

• Length: 10

• Multiplicity: [0..1]

Roundabouts smaller than 450m² are represented as point features, and the roads are extended to meet at the centre point. Mini roundabouts are not included.

Roundabout attributes

classification

The classification of the Roundabout. The valid values are defined in the RoundaboutClassification Code List.

• Type: RoundaboutClassificationType

• Length: 45

• Multiplicity: [1]

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Point representing the alignment of the roundabout.

• Type: GM_Point

• Multiplicity: [1]

An electric vehicle charging station, also called EV charging station, electric recharging point, charging point, charge point and EVSE (Electric Vehicle Supply Equipment), is an element in an infrastructure that supplies electric energy for the recharging of electric vehicles, such as plug-in electric vehicles, including electric cars, neighbourhood electric vehicles and plug-in hybrids.

CarChargingPoint attributes

chargeMethod

Determines the type of current used in charging.

• Type: ChargeMethod

• Length: 15

• Multiplicity: [1]

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

The location of the car charging facility is represented as a point feature.

• Type: GM_Point

• Multiplicity: [1]

ratedVoltage

The voltage available at the car charging point. Higher voltage levels charge batteries more rapidly.

• Type: RatedVoltage

• Length: 3

• Multiplicity: [1]

type

The type of connector. This is determined by whether an EV is charged using AC or DC, the charging speed (kW power) and the safety protocol employed. Having different countries of origin, the make and model will also determine what connector are used.

• Type: CarChargingType

• Length: 27

• Multiplicity: [1]

Point feature representing the approximate location of numbered junction on a Motorway.

MotorwayJunction attributes

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Point feature representing the approximate location of numbered junction on a Motorway.

• Type: GM_Point

• Multiplicity: [1]

junctionNumber

The motorway junction number assigned by the Department for Transport.

• Type: CharacterString

• Length: 10

• Multiplicity: [1]

The guides below detail how to load raster data for the following products:

Open ‘PG Admin’ from the Windows desktop and, using the menu options available, create a new database and a new schema within the database to hold the OS OpenMap-Local data. It is recommended that the user not use the ‘public’ schema to hold the data itself.

In the example above, a database called ‘osopenmap’ has been created along with a schema called ‘openmap’ into which the data will be loaded. As the data to be loaded comes in shapefile format, there is an easy to use PostGIS plugin available within PostgreSQL to load shapefile data.

Select ‘plugins’ from the main menu followed by ‘PostGIS Shapefile and DBF Loader’

The next window allows the user firstly to view connection details and then to add files to the database. The first thing to do will be to test connection details. Click on the ‘view connection details’ button.

The resulting box should contain the username and password already entered along with the host name. The database being used to contain the data should already be selected. Click ‘OK’

If everything is working OK, ‘connection succeeded’ should appear in the Log Window. Click the ‘Add File’ button.

In the next box which appears, use the file tree in the ‘Places’ box on the left to navigate to the folder in which the OS OpenMap-Local data resides. A list of the files will appear in the main window. It is possible to load one or all of the files into the database. In the example below, all of the shapefiles have been selected. The click ‘Open’.

Another window will open listing the selected shapefiles. The Schema and SRID will need to be changed. The schema will need to be changed to the schema in the database into which the data is being loaded (in this case ‘openmap’). The SRID (or co-ordinate reference system) will need to be changed to 27700, which is the code for British National Grid. This will need to be done for all of the shapefiles being loaded. No other element will need to be changed. Once this has been done click ‘Import’.

At the end of the procedure, the log window at the bottom of the PostGIS import/export manager box should indicate that all of the shapefiles have loaded successfully. However one or two of the shapefiles may fail to load because the text encoding needs to be changed from UTF-8 to LATIN1. If this is the case, the user will need to close down the plugin and start again selecting just the shapefiles which failed to load previously. The schema and SRID must be changed again and this time, the character encoding will need to be changed. This can be done by clicking the ‘options’ button;

Change the DBF character encoding to LATIN1 and click ‘OK.

Changing this should allow the import to complete successfully. For information, the shapefiles which are mostly likely to need this change to be made are the ‘named place, important building and functional site’ files. This is because these files contain text which may have accents within them which are not part of the UTF-8 character set.

Once the import has been completed, the user can check if the data is loaded properly by refreshing the schema in PGAdmin and opening up the ‘table’ tree. If the data has loaded correctly, there should be 20 tables in the schema.

The data is now loaded into the PostGIS database and is now ready to be viewed in a GIS application. As QGIS, the open-source GIS, has been developed to work seamlessly with PostGIS, we will open up and view the data using that application. However, any GI application which includes support for PostGIS can be used.

OS OML can support a wide range of customer applications that utilise geographic information. The product is ideal for providing backdrop mapping on websites and displaying business locations on small-scale 'street level' maps.

Backdrop mapping on a website

OS OML has been designed for on-screen use, with generalised detail and an appropriate level of content that gives an uncluttered appearance.

The layered structure of the vectorised versions of OS OML enables you to display a map to show only the features you want to show (for example, roads, place names and buildings). In contrast, the rasterised version provides you with a pre-rendered and styled 'out of the box' backdrop mapping solution.

In both cases, you have the option to fade the map backdrop to ensure that your own or third-party overlaid data is clearly portrayed. This can be useful in cases where you need to draw attention to a specific point or feature.

Backdrop mapping is often used by public sector organisations to share information with the public, for example, providing the public with the location of GP surgeries or dentists within a set area.

Assessing local sites of interest

OS OML lets you easily assess local sites of interest (for example, educational facilities), highlighting their location and context within an area. The backdrop style of the product gives great insight into an area while allowing the chosen data to stand out.

Identifying hotspots in data within local areas

OS OML allows you to quickly identify hotspots in data (for example, recorded crime location or property prices) for representation within a local area. The muted colours of the detailed backdrop map give your information more prominence.

Displaying the location of a business

The local view of OS OML is ideal for creating a map of a street or neighbourhood to share the location of your business, complete with street and locality names to provide context.

OS OML features are generalised representations, but they still hold an instantly recognisable geometry to their associated real-world object. These objects include things like buildings, roads, railways and rivers. It also includes notable sites, such as schools, hospitals and transport hubs, with important buildings specifically identified within those sites. These notable sites are accompanied by non-topographic features, such as cartographic text and symbols.

The data structure applies to the GML, ESRI shapefile and GeoPackage.[KS1]

UML diagram and table conventions

The data structure is described in this section by means of unified modeling language (UML) class diagrams and accompanying tables containing text. The UML diagrams conform to the approach specified in ISO 19103 Conceptual schema.

Colour conventions have been used in the diagrams and tables to distinguish the properties that have been added in this specification. In the UML diagrams, classes in the Ordnance Survey product specification are orange. All code lists are coloured blue. Therefore, the tables which follow in this Technical Specification use orange for a feature type and blue for a code list.

Stereotypes

The following stereotypes are used on UML elements:

Formats

OS OML is available in the following formats:

• Vector: GML (Geography Markup Language) v.3.2.1 Simple Features and schema, which is zipped as a single file using gzip

• Vector: ESRI shapefile, with each tile dataset zipped using gzip

• Vector: GeoPackage, with a single zipped file for a national set (Great Britain)

• Raster: GeoTIFF, compressed using LZW (Lempel-Ziv-Welch), is a TIFF file which has geographic (or cartographic) data embedded as tags within it. The geographic data can then be used to position the image in the correct location and with precise geometry on the screen of a geographic information display

PostGIS is the geospatial extension to the free open-source database application PostgreSQL. The PostGIS extension needs to be installed as part of the PostgreSQL install. Instructions of how to do this can be found on the OS Web Site;

A built entity that includes a roof. This is a generalised building and could be made up of an amalgamation of other buildings and structures.

Building attributes

The following sub-sections provide details about the attributes included with this feature, their data types in the different output formats, and other important metadata about them

featureCode

A unique feature code to facilitate styling.

• Type: integer

• Multiplicity: [1]

geometry

Polygon representing the generalised building.

• Type: GM_Surface

• Multiplicity: [1]

Loading GML data into ArcGIS

The GML data can be imported into ArcGIS using the Quick Import function in Arc Toolbox. The data will be imported un-styled. Users should also note that due to the large file sizes of some of the 100km2 grid tiles especially SU and TQ, this import may take time to process.

The quick import will create a special file geodatabase into which to import the data. Once the quick import function has been completed, the data can be added using the usual ‘add data’ button in ArcMap and selecting all of the layers from the newly created file geodatabase;

The resulting imported data will then appear in the ArcMap window and can then be styled according to user requirements.

The data can also be styled with a suitable ArcGIS layer file for OS OpenMap-Local previously created or styled manually using the styling tools provided.

Loading GML data into MapInfo Professional

OS OpenMap-Local is supplied in GML version 3.2.1. At the current time, most versions of MapInfo Professional will not import this version of GML data. Version 12.5 of MapInfo Professional does read the latest version of GML data but this has not been tested. The only alternative way of loading GML data to MapInfo would be to use third party translation software. Some of this is open-source and some is commercial.

A building constructed largely of glass for the purposes of commercial horticulture. This is a generalised glasshouse and could be made up of an amalgamation of individual glasshouses. Only glasshouses larger than 5 000m² are included.

Glasshouse attributes

featureCode

A unique feature code to facilitate styling.

• Type: integer

• Multiplicity: [1]

geometry

Polygon representing the generalised glasshouse.

• Type: GM_Surface

• Multiplicity: [1]

Cables used to supply electricity that are suspended between pylons.

ElectricityTransmissionLine attributes

featureCode

A unique feature code to facilitate styling.

• Type: integer

• Multiplicity: [1]

geometry

Line representing the alignment of the electricity transmission line.

• Type: GM_Curve

• Multiplicity: [1]

It is possible to load multiple 100km² grid tiles of data into the same schema in PostgreSQL. As the shapefiles have the 100km grid letters as a prefix in the filename, these files will go into separate tables in the schema. It will then be possible to view data across tile edges using QGIS or other GI applications which support PostGIS.

The screenshot above shows data from the SU grid tile (styled) and the buildings and roads from the TQ grid tile (un-styled). However, it should be noted that duplicate features will exist across the tile edges as the data is supplied as ‘hairy tiles’ as previously indicated.

Removing duplicate features in PostGIS

As stated above, if using multiple tiles of data in PostGIS, loading them as described, some features will replicated across tile edges loaded in different tables of the same features, e.g. in SU_Buildings and TQ_Buildings. If the data is being used for contextual purposes only, this should not be an issue for the user. However, if the data is being used for any kind of analysis involving counts of features, these duplicates will need to be removed to avoid providing spurious results.

It is possible to remove these features using SQL commands in PostgreSQL itself.

Using SQL Commands

Firstly, create a merged file containing the area required using the merge shapefile feature in QGIS documented earlier. In this example, the roads from TQ and SU will be merged. Once created, these merged shapefiles can be loaded into PostgreSQL using the shapefile loader plugin as described above.

Check to see that the merged file has been loaded. This table will contain duplicate features across the tile edges. Using the SQL window in PostgreSQL, a count of the features within the file can be determined using the following command;

SELECT COUNT(id)
FROM openmap.os_openmap_su_tq_roads
;

In the case above the command is querying the table os_openmap_su_tq_roads in the schema openmap used previously in this guide. The count returned will be as follows in this example;

Using the following command, a new table called os_openmap_su_tq_roads_dissolved will be created in the same schema osopenmap;

CREATE TABLE openmap.os_openmap_su_tq_roads_dissolved AS
SELECT id, distname, roadnumber, classifica, featcode, ST_UNION(geom) AS geom FROM openmap.os_openmap_su_tq_roads
GROUP BY 1,2,3,4,5
;

Finally the following command will provide a count of the features in the newly created dissolved table;

SELECT COUNT(id)
FROM openmap.os_openmap_su_tq_roads_dissolved
;

The result of this query is as follows;

The user can see, from running this query that the number of features in the newly created table is less that in the original merged table. This indicates that the duplicate features along the tile edges have been removed. It will now be possible to load the dissolved table into QGIS and carry out the required analysis.

Using a graphical method in QGIS

An alternative way to do what has been described above would be to merge the required shapefiles together and de-duplicate using QGIS as described earlier in this document. The user will then have a set of de-duplicated shapefiles which can then be loaded into PostgreSQL/PostGIS and displayed in QGIS using the methods described previously.

The guides below detail how to load vector data for the following products:

All railways are represented as lines and are broken where they pass under bridges, buildings or other obstructing detail. Railway sidings and the tracks of travelling structures are not included.

RailwayTrack attributes

classification

The classification of the RailwayTrack. The valid values are defined in the RailwayTrackClassification Code List.

• Type: RailwayTrackClassification

• Length: 45

• Multiplicity: [1]

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Point representing the position of the railway track.

• Type: GM_Curve

• Multiplicity: [1]

Railway tunnels are represented as approximate centrelines of the railway that runs through the tunnel.

RailwayTunnel attributes

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Line representing the alignment of the railway tunnel.

• Type: GM_Curve

• Multiplicity: [1]

Point feature representing the buildings and platforms by a railway line where a train may stop to pick-up or drop-off goods or passengers.

RailwayStation attributes

classification

The classification of the RailwayStation. The valid values are defined in the RailwayStationClassification Code List.

• Type: RailwayStationClassification

• Length: 65

• Multiplicity: [1]

distinctiveName

The name of the station, consistent with the names used by National Rail Enquiries. The suffix ‘Station’ is not added to the name.

• Type: CharacterString

• Length: 150

• Multiplicity: [1]

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Point representing the position of the railway station.

• Type: GM_Point

• Multiplicity: [1]

The part of the shore or beach which lies between the Low Water Mark and High Water Mark defined by the TidalBoundary. The same condition may exist in non-contiguous offshore areas.

Foreshore attributes

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Polygon representing the area of foreshore.

• Type: GM_Surface

• Multiplicity: [1]

In QGIS, click on the ‘open PostGIS layer’ button on the left hand side of the window.

In the next window, a new connection will have to be set up to the newly created database containing the OS OpenMap-Local data. Click on ‘new’. Another window called ‘create PostGIS connection’ will appear. Information will be required to be entered into this window to set up the new connection.

In this example, the name ‘osopenmap’ for the connection has been provided along with the name of the database which holds the data. Click on the ‘Test Connect’ button to ensure that the correct connection is made. Once successful, click ‘OK’. If the save username and save password boxes have been clicked, click ‘OK’ in the subsequent message box.

A new connection will now be available in the list of PostGIS database connections. Ensuring that the correct one is listed, click on ‘connect’. The schema containing the OS OpenMap-Local data can be seen.

Click on the + sign next to the schema to expand the list of tables. Select all of the tables within OS OpenMap-Local that are required to be loaded to QGIS. Once all have been selected, click ‘Add’.

The OS OpenMap-Local data will load into QGIS. The data will need to be re-ordered and then styled appropriately using personalised style files or the style files available from GitHub published by Ordnance Survey. If using these published files, please consult the accompanying ‘Quick Start Guide’ as to their use. It should be noted that there is no requirement to add a spatial index to the data from PostGIS as those indexes were added automatically during the loading of the data into PostgreSQL.

If using the published style files, the output should appear as shown above.

An inland waterway body sufficiently wide enough to capture as an area feature. Small lakes and small islands in waterbodies are not included.

SurfaceWater_Area attributes

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Polygon representing the area of surface water.

• Type: GM_Surface

• Multiplicity: [1]

An inland waterway body not sufficiently wide enough to capture as an area feature.

SurfaceWater_Line attributes

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Line representing the alignment of the surface water.

• Type: GM_Curve

• Multiplicity: [1]

A generalised building that belongs to a FunctionalSite.

FunctionalSite attributes

BuildingTheme

A description of the theme that a particular site falls under (that is, air transport, education, medical care and so on.). The valid values are defined in the SiteThemeType Code List.

• Type: BuildingTheme

• Length: 27

• Multiplicity: [1]

classification

A description of the actual function of a site (that is, airfield, junior school, hospital and so on.) The valid values are defined in the SiteClassification code list. For sites with multiple functions, the values will be provided together and separated by a ‘,’.

• Type: SiteClassification

• Length: 90

• Multiplicity: [1]

distinctiveName

The name of the site (for example, ‘Brighton College’). Note this may be null if the captured value is a house number.

• Type: CharacterString

• Length: 120

• Multiplicity: [0..1]

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Polygon representing the generalised important building.

• Type: GM_Surface

• Multiplicity: [1]

siteTheme

A description of the theme that a particular site falls under (that is, air transport, education, medical care and so on.). The valid values are defined in the SiteThemeType Code List.

• Type: SiteTheme

• Length: 21

• Multiplicity: [1]

A polygon feature that represents the area or extent of certain types of function or activity with appropriate attribution.

FunctionalSite attributes

classification

A description of the actual function of a site (that is, airfield, junior school, hospital and so on.) The valid values are defined in the SiteClassification Code List. For sites with multiple functions, the values will be provided together and separated by a ‘,’.

• Type: SiteClassification

• Length: 90

• Multiplicity: [1]

distinctiveName

The name of the site (for example, ‘Brighton College’). Note this may be null if the captured value is a house number.

• Type: CharacterString

• Length: 120

• Multiplicity: [0..1]

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Polygon representing the extent of the functional site.

• Type: GM_MultiSurface

• Multiplicity: [1]

siteTheme

A description of the theme that a particular site falls under (that is, air transport, education, medical care and so on.). The valid values are defined in the SiteThemeType Code List.

• Type: SiteTheme

• Length: 21

• Multiplicity: [1]

Code list: RailwayTrackClassification

Polygons defining the extents of tidal water, up to the High Water Mark defined by the TidalBoundaries and the Normal Tidal Limit of rivers. Tidal water is not included under bridges.

TidalWater attributes

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Line representing the alignment of the tidal water.

• Type: GM_Curve

• Multiplicity: [1]

Code list: DrawLevelValue

A representative point feature giving the general location of a settlement name or geographic place name, for the purposes of text placement.

NamedPlace attributes

classification

The classification of the NamedPlace. The valid values are defined in the NamedPlaceClassification Code List.

• Type: NamedPlaceClassification

• Length: 40

• multiplicity: [1]

distinctivename

The settlement name or geographic place name. When a place is dual named, the Welsh or Gaelic name is presented first, followed by a space, a forward slash, a space and then the English name.

• Type: CharacterString

• Length: 100

• Multiplicity: [1]

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

fontHeight

A suggested text size to use for placing the distinctiveName as cartographic text. For most names, the text size is proportional to the size of the area to which the name applies. For valleys, the text size is based on the valley length, and for hills/mountains, the text size is based on the height of the summit. The valid values are defined in the FontHeightClassification Code List.

• Type: FontHeightClassification

• Length: 11

• Multiplicity: [1]

geometry

Point representing the cartographic position of the named place.

• Type: GM_Point

• Multiplicity: [1]

textOrientation

Suggested text orientation (in degrees) to use for cartographic text placement of valley names, names of stretches of water and estuaries.

• Type: Measure

• Multiplicity: [1]

In England and Wales, these tide lines will be the levels of mean tides, i.e. of a tide between a spring and neap tide. In Scotland, the tide lines are those of mean spring tides. In places where there is no Foreshore (e.g. vertical cliffs), the TidalBoundary is classified as the 'High Water Mark'.

TidalBoundary attributes

classification

The classification of the TidalBoundary. The valid values are defined in the TidalBoundaryClassification Code List.

• Type: TidalBoundaryClassification

• Length: 45

• Multiplicity: [1]

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Line representing the alignment of the tidal boundary.

• Type: GM_Curve

• Multiplicity: [1]

Areas of trees (coniferous, non-coniferous and mixed) are represented as polygons. Small areas of woodland are omitted and small clearings in woodland are filled.

Woodland attributes

featureCode

A unique feature code to facilitate styling.

• Type: Integer

• Multiplicity: [1]

geometry

Polygon representing the area of woodland.

• Type: GM_surface

• Multiplicity: [1]

Code list: RoundaboutClassification

Determines the type of current used in charging.

Code list: ChargeMethod

Code list: OverrideValue

Code list: RatedVoltage

Code list: RailwayStationClassification

Code list: RoadClassification

Code List: TidalBoundaryClassification

Code List: CarChargingType

The type of connector. This is determined by whether an EV is charged using AC or DC, the charging speed (kW power) and the safety protocol employed. Having different countries of origin, the make and model will also determine which connector are used.

Code List: FontHeightClassification

OS OpenMap - Local - XML schema

Available as a link from the product page here.

OS Open Map - Local - Legend

The legend provides a full list of features and their styling in the raster format – available as a PDF download from the product page here.

Code List: SiteClassification

Code List: BuildingClassification

Code List: NamedPlaceClassification

Code List: BuildingTheme