OS Emergency Services Gazetteer

A Lightning Talk

What is the Emergency Services Gazetteer (OS ESG)​

The OS Emergency Services Gazetteer product is a comprehensive and maintained gazetteer of locations including names, places, and objects.​

• Aligned to the AddressBase Premium Format.​

• Every feature in OS ESG will have a Unique Property Reference Number (UPRN).​

• Coverage is England, Scotland and Wales.​

• A set of granular classifications types. ​

• Comprises of the Basic Land Property Unit (BLPU), Land Property Identifier (LPI) and Classification components ONLY.​

• Published monthly in GeoPackage and CSV formats.​

How can you use the OS ESG​

The OS ESG provides a national, consistent and maintained view of the locations. Currently these are Named Junctions and Geographical Names, but with a wider range of features in future releases​

It enables quick and accurate gazetteer searches and visualisation in applications and supports incident response, planning and coordinating emergency responses, situational awareness and incident reporting.​

March 2024	Future Releases
Names and Numbers of Junctions	Bridge Interactions
Geographical Names	Tunnels
	Slipways
	Weirs
	Motorway Marker Posts
	Motorway Emergency Phones
	Vernacular Names

What data format is the OS ESG supplied in?​

OS ESG will be made available via the OS Data Hub, as part of Premium Downloads.​

• The GeoPackage format comes ready to load into the GIS package of the users choice with different gpkg files for each layer. You will need to join the data using the UPRN.

• The CSV format is more suited for loading into a database. All of the same feature types are accessible in csv format and all the same attribution as the Geopackage, however instead of storing the geometry in a GIS ready format, ‘BLPU’ for example is stored as a POINT attribute with a co-ordinate pair for each point.​

What is the OS ESG attribution?​

​The OS ESG will align to the AddressBase Premium specification, in line with user requirements. Therefore, it will be structured as a series of relational tables:​

• Basic Land and Property Unit (BLPU) - a real-world object that is ‘an area of land, property or structure of fixed location having uniform occupation, ownership or function’.​

• Local Property Identifier (LPI) - a structured entry that identifies a BLPU. The AddressBase Premium data structure provides the facility to describe a BLPU by more than one LPI. In England and Scotland there will be one Approved LPI, while in Wales there will be two Approved LPIs (English and Welsh)​

• Classification - a structured entry that provides the code for the type of feature.

OS ESG Geographical Names​

The data includes names of features and places of geographic significance, providing orientation and identity. ​

A subset of the existing OS NGD Geographical Names, such as named water and geographic features, will be provided as part of OS ESG.​

The data offers a comprehensive list of names of features such as hills, valleys, cliffs and waterfalls.​

Differences between OS ESG Geographical Names & OS NGD Named Point​

OS ESG Geographical Names is a subset of the OS NGD Named Point Feature. For example, woodlands aren’t in OS ESG as they are included within AddressBase Plus and AddressBase Premium​

OS ESG Names and Numbers of Junctions​

A named intersection between roads at a junction or roundabout. The intersection will be assigned a modelled name based on the names of the intersecting roads and may have a number or an official name. The feature will have a classification code and description also e.g. CT14MJ Numbered Motorway Junction​.

Junction features will be provided for junctions where two or more named or numbered roads intersect. The SAO Text field can include Alternate Road Names. These can be a different spelling or an alternate road name​.

Examples of road junctions (click to enlarge)

OS ESG Junction compared with OS NGD Named Road Junction​

Geometry: Motorway Junctions and Roundabouts are a single point geometry in OS ESG and Multipoint geometry in OS NGD Named Junctions​

​Schema: OS ESG is in an AddressBase Premium format and OS NGD Named Junctions have an OS NGD schema​

​Attribution: OS ESG has an AREA_NAME. There is no AREA_NAME on the OS NGD Named Junction feature​

​Classification: OS ESG has a classification scheme and OS NGD Named Junction has a description​

OS ESG Bridge Interactions​

This data provides information about bridges, describing the interactions with the networks below and over the bridge using a parent and child data relationship. This is similar to the data is OS NGD structures, only more detailed.​

​The data has been modelled and automatically created by OS using Topographic, Transport Network, Water Network, and Structures data.​

​There are 54 bridge interaction classification codes to give an overview of the type of networks that cross over and under the bridge e.g. Footbridge Over Canal.​​

Attribution	Definition	Indicative Values ​
PAO text​	Primary Addressable Object (PAO) name or description. Used to record the bridge name. Where the official name has not been captured by OS, then Bridge Unknown Name will be used.​	Abbey Bridge​ Abercamddwr Bridge​ Bridge Unknown Name​
SAO text​	Secondary Addressable Object (SAO) name or description. Used to record the names and numbers of intersecting network features or the type of network where no names apply.​	Duck Mill Walk Over River Great Ouse​ A483 Over Camddwr​ Railway between Glenfinnan and Locheilside Over A830​ Broughton​
Parent UPRN​	UPRN of the parent Record, if a parent- child relationship exists. This is used to relate individual intersections to the parent bridge feature where there are multiple intersections between different networks at the same bridge. This attribute is NULL for features where either there is no parent-child relationship or the BLPU itself is a parent bridge BLPU.​	996001447292​ NULL ​
Multi Occ Count​	Count of all of the child UPRNs for this record where a parent-child relationship exists; otherwise it will be set to 0.​	3​ 5​

​

OS ESG Bridge Interactions user information​

Parent & Child UPRN Relationship​:

The Parent UPRN in this dataset is for the named bridge itself, in this case ‘Queen’s Bridge’ and lists all the interactions ‘Road Bridge over Multiple’. The Child UPRNs represent the individual interactions of the bridge over other networks, in this case the Norrie-Miller Riverside Walkway and the River Tay.​

Completeness​

The following bridges will be excluded:​

• A subset of these features is already available in OS Addressing. To avoid duplicating features, these features will be excluded from the OS ESG product. ​

• Unnamed bridges (including footbridges) with no networks crossing over them and unnamed watercourse passing beneath them​

• Unnamed footbridges with unnamed paths crossing over them and either unnamed watercourse or no network passing beneath them.​

​OS ESG data can be used alongside OS NGD ​

Network over and under information is provided in OS ESG for bridges represented in OS NGD Compound Structure data. The main difference being that OS ESG is point data, not polygon data like OS NGD.​

​Rail Station Detail​

For a bridge that crosses a rail line the station information is provided, especially as a number of these are unnamed. With station information it is easier to pinpoint which section of track the bridge is on. ​

LPI: Area Name and Address​

In OS ESG as there is a hierarchy of assigning an LPI area name, it is derived from: ​

1. The OS NGD Geographical Names Named Area Polygon if it is within one (this may have a different extent to the locality of the same name in Addressing data)​

2. (NEAR) indicates either within 1 km of a settlement onshore, or within 500 m of a named island or 1 km from a Lower Tier Local Authority if the point is offshore​

3. In non-urban areas the Lower Tier Local Authority is provided. ​

The OS ESG feature area name can include a combination of polygon descriptions based on hierarchy e.g. Suburban Area, Other Urban Area, City​

The address & street data in your 999 Control system that the OS ESG may sit alongside may have a locality field in some instances. This locality information may differ from the Area Name in OS ESG as they come from a different source

LPI: USRN Assigned to BLPU​

The USRN is supplied as part of the OS ESG is to allow compatibility with AddressBase Premium so it can be used with existing import tools​

When assigning the USRN to a junction, the USRN of the lowest classification Street within AddressBase intersecting a junction is assigned e.g. if you have a Designated Street Name and Officially Described Street then the Officially Described Street is selected, see StreetRecordTypeCode in the AddressBase Premium Technical Specification. ​

If there are multiple Streets with the same lowest classification, the USRN of the shortest Street intersecting a junction is assigned.​

Where roads intersecting a junction do not have an associated Street and hence a USRN, the USRN of the nearest non-motorway Street is assigned.​

The OS ESG will only reference USRNs that are in AddressBase Premium​.

examples of USRNs being assigned to ESG records (click to enlarge)

OS ESG Junction compared with OS NGD Named Road Junction​

Geometry: Motorway Junctions and Roundabouts are a single point geometry in OS ESG and Multipoint geometry in OS NGD Named Junctions​

Schema: OS ESG is in an AddressBase Premium format and OS NGD Named Junctions have an OS NGD schema​

Attribution: OS ESG has an AREA_NAME. There is no AREA_NAME on the OS NGD Named Junction feature​

Classification: OS ESG has a classification scheme and OS NGD Named Junction has a description​

Comparison of OS ESG and OS NGD data

Looking at the OS NGD Geographical Names Lightning Talk may also be of benefit.

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Links that may be useful:

OS Emergency Services Gazetteer | OS Download Products' Documentation

OS Select+Build | Data Products | OSOrdnance Survey

This content has been developed from what was originally a Lightning Talk PowerPoint slide set. These slides are available to PSGA members to view and download from the PSGA members area of the OS website