What OS MasterMap Topography Layer provides you with
Mapping from the ground up
In a business of any kind, OS MasterMap Topography Layer gives you the confidence to make location-based decisions about assets, services, environmental risks, customers and operations.
Geo-tag your assets, with the topographic identifier (TOID) at the heart of OS MasterMap products. This makes it ideal for monitoring assets such as pipelines, pylons, bridges and warehouses.
OS MasterMap Topography Layer includes enhanced features - Building Height Attribute to analyse the built environment and Sites Layer showing the main points of access to key sites.
The foundation of the OS MasterMap family
With OS MasterMap Topography Layer, each feature is a record in a database. Each of these records has information about the feature’s position and shape on Earth – its geometry – as well as details about it termed ‘attributes’. It provides an accurate visual context to help you interpret addresses, routes and imagery provided by the other layers.
Need more technical information?
Read product guides, technical specification and further documents and support.
- Use cases
The user may use the Topography Layer in a wide variety of ways, including:
- improving a user’s data capture processes and the accuracy of a user’s own derived data
- aiding the visual clarity of data and the visual interpretation of data
- achieving consistency and maintainable standards within geographic data holdings
- enhancing the queries that can be run on their data and so providing better information for decision making
- establishing a common reference between a user’s own datasets and data they may wish to share with other organisations
- using the products in an integrated manner to derive additional information
- identifying and managing change in their area of interest
- creating historical views of their area of interest
A common use for the product is by organisations who have their own GI and wish to examine it in relation to the real world around them. An example would be utility companies that have assets both at surface and below surface level. They frequently need to visit these assets, either for repair, maintenance or to add new assets. By viewing their infrastructure against the features in OS MasterMap Topography Layer, it will help their crews locate the assets, become familiar with the area before they leave their depot and allow them to provide a better user service by identifying those nearby premises that need to be notified about the works.
- Data theme
- Land Use
- Administrative and Statistical Units
- Data structure
- Vector - Identifiers
- Great Britain
- 1:1250 to 1:10,000
- GML 2.1.2
- Ordering area
- All of Great Britain or customisable area (5km2 tiles or user defined polygon)
- OS Data Hub plan
- Premium Plan
- Public Sector Plan
Documents and Support
Getting started guides
- OS MasterMap Topography Layer - OverviewThe overview introduces the product and gives context for all users. It highlights key features, provides examples of potential uses for the product and lists details like file sizes, supply formats, etc.v3.1897 kbMarch 27, 2023
- OS MasterMap Topography Layer - Getting started guideThe getting started guide provides instructions for using the product in different software applications. Users with limited technical knowledge will be able to follow this guide.v1.63.3 mbFebruary 10, 2023
- Getting started with GeoPackageThis guide helps you to get started using GeoPackage - a lightweight format that can contain large amounts of complex data in a single, easy to distribute and ready to use file.v21.11 mbSeptember 30, 2021
- Getting started with vector tilesThis guide will help you to get started using vector tiles (MBTiles) – lightweight tiles that are efficient and quick to render in your software, letting you create customised, high-resolution, beautiful mapping.v1845 kbSeptember 23, 2022
- OS MasterMap Topography Layer - Technical specificationThe technical specification provides detailed technical information about the product. It is targeted at technical users and software developers.v1.62.3 mbFebruary 7, 2023
- OS MasterMap - Real-world object catalogueThis catalogue lists the real-world objects (RWOs) present in OS MasterMap data and the features and attributes associated with them.v112.0 mbNovember 8, 2001
- OS MasterMap Topography Layer - Styling getting started guideThis document provides information on how to style the OS MasterMap Topography Layer product. For related styling information, please refer to the Standard Styling Specification.v1.63.1 mbFebruary 10, 2023
- OS MasterMap Topography Layer - Standard styling specificationThis document provides information on the Standard Styling Specification for the OS MasterMap Topography Layer product.v1.63.0 mbFebruary 10, 2023
- Product refresh datesFind out the update frequencies of our premium products and the calendar months that they are updated.link
- OS MasterMap Topography Layer - Release noteThis release note provides information about the latest release of OS MasterMap (OSMM) Topography Layerv11,645 kbFebruary 19, 2024
The need for a national topographic dataset
OS MasterMap Topography Layer was developed in response to the need for a national topographic dataset that offers users a more sophisticated type of data that represented the world in a more realistic way and was more aligned to the increasing use and functionality of GIS and spatial database technology within organisations.
The advantages of TOIDs as a referencing system
Each and every feature within OS MasterMap has the TOID (TOpographic IDentifier) as a unique reference. This makes it possible to identify any single feature within the dataset without any ambiguity.
Current referencing systems, such as coordinates and addresses, are subject to interpretation between users. This creates fuzzy matching issues between organisations wanting to exchange data; for example, will the building St James House be picked up in another system where it is spelt St James' House?
TOIDs will stay the same throughout the life cycle of each feature. In other words, if a feature changes, the TOID will stay the same as long as it is deemed to be the same feature; for example, a house having an extension built is still the same house and fulfils the same purpose. This provides a continuity of reference even though a feature may undergo changes. This makes the TOID a robust referencing system that customers can use alongside, or instead of, their own referencing systems and can link to their own information about the feature. Having unique references is essential to making the most out of storing data within a relational database management system, as these rely on unique referencing to be able to store, sort, manage, query and retrieve data efficiently.
Types of real-world objects represented in the Topography Layer
Please see our real-world object catalogue (PDF). It lists every type of real-world object in the OS MasterMap Topography Layer specification, and details how it is represented by Topography Layer features.
Accuracy of OS Mastermap Topography Layer
We define accuracy in three ways:
- Absolute accuracy – how closely the coordinates of a point in the dataset agree with the coordinates of the same point on the ground (in the British National Grid reference system).
- Relative accuracy – positional consistency of a data point or feature in relation to other local data points or features within the same or another reference dataset.
- Geometric fidelity – the ‘trueness’ of features to the shapes and alignments of the objects they represent when testing the data according to the dataset specification against the ‘real world’ or reference dataset.
Available scales for OS MasterMap Topography Layer data
For cartographic representation, OS MasterMap Topography Layer is captured and designed for display at 1:1250, 1:2500 and 1:10 000 scales in urban, rural and mountain/moorland areas respectively.
In GIS OS MasterMap can be viewed over a considerable range of scales. The most scale-sensitive feature types, such as cartographic text and symbol features, are fixed in size and rapidly become less clear at smaller display scales (that is, when zoomed out).
OS MasterMap Topography Layer is also suitable for use in non–cartographic applications where the concept of scale is less applicable.
Get this product
What you get
- Key features
- Mapping from the ground up
- Accurate referencing
- Enhanced features
- The foundation of the OS MasterMap family
- Data structure
- Vector - Identifiers
- Update frequency
- Every six weeks
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