How accurate is OS MasterMap?
How accurate is OS MasterMap Topography Layer?
| Original survey scale | 99% confidence level | RMSE* |
|---|---|---|
| Absolute accuracy | 2.4m | 1.1m |
| Relative accuracy | +/- 2.5 m (up to 100m) | +/- 1.0 (up to 100 m) |
| 1:10 000 | ||
| Absolute accuracy | 8.8m | 4.1m |
Are Ordnance Survey maps topographic?
OS MasterMap Topography Layer is comprised of 500 million individual features, each assigned a unique Topographic Identifier (TOID). This identifier is connected to that feature throughout its lifecycle and retired when the feature is removed if, for example, a building is demolished.
What is a topography layer?
The Topography Layer helps in the planning and management of land and property by enabling users to visualise the context of any feature or site, to pinpoint individual properties and precise sites when a high level of detail is required, and to assess the impact of a proposed development effectively and efficiently.
What is master map?
: an original usually large-scale map which is made directly from surveys and from which other maps are derived.
What is OS Open Data?
OS OpenData provides free digital maps of Great Britain, available for any purpose. Free downloadContact us.
Where can I find contour maps?
Use the Nat Geo Topo! Explorer website to find and display a contour map of your area. Point out the contour lines.
How are contour lines drawn on maps?
Contour lines are lines drawn on a map with equal elevation points, so elevation would be constant if you followed the contour line physically. The elevation and terrain shape of the contour lines shows. It is useful because they show the form of the land surface on the map–its topography.
How do I get a site location plan?
You can buy both types of plan through one of the Planning Portal’s accredited suppliers. A location plan shows the proposed development in relation to its surrounding properties. It must be based on an up-to-date map and at an identified standard metric scale (typically 1:1250 or 1:2500).
What is the OS map?
Ordnance Survey (OS) is the national mapping agency for Great Britain. Ordnance Survey mapping is usually classified as either “large-scale” (in other words, more detailed) or “small-scale”. The Survey’s large-scale mapping comprises 1:2,500 maps for urban areas and 1:10,000 more generally.
How do I download OS maps to my phone?
Use the OS Maps app to download sections of map for use offline. In the app select Menu > My Offline Maps and click ‘ Add a custom offline map (Menu > Download offline maps on Android). Find the area you want to download. Click ‘Download’ to save the area on screen plus about the same in each direction and name it.