Ordnance Survey data tile structure
Introduction
Ordnance Survey supply the data for each of their products in square tiles. The area covered, and the file size of each of these tiles differs for each of the products available through Digimap. For most of the products these tiles are simple and consistent.
Note: Land-Line.Plus® data was withdrawn from Digimap on 2 September 2008. Digimap users are entitled to continue using existing holdings of these data until 31 July 2009 when the licence agreement under which the data were offered expires. Th OS MasterMap® data that has replaced it is a seamless dataset that has no tiles. More information can be found here: OS MasterMap® Topography layer.
Each tile is given a name indicating its location in the GB National Grid: the name of each tile is a Grid reference indicating its extent. An explanation of grid references can be found here: National Grid References - An introduction.
The tiles for many of the Ordnance Survey products within Digimap are periodically updated. The Ordnance Survey's policy on updating the data and distributing updates to Digimap can be found here: Revision and Update of Ordnance Survey Products.
This page explains the ground area covered, the file size and arrangement of these tiles for each product. Click on a product name below to jump to the relevant section of this page.
- Strategi® tile structure
- Meridian™ 2 tile structure
- Land-Form PANORAMA™ tile structure
- Land-Form PROFILE™ tile structure
- 1:10,000 Colour Raster tile structure
- 1:25,000 Colour Raster tile structure
- 1:50,000 Colour Raster tile structure
Strategi® tile structure
There are two Strategi® tiles for SHP, MID/MIF, DXF and NTF. Strategi® tiles GBNORTH and GBSOUTH cover the whole of Great Britian, with GBNORTH and GBSOUTH covering areas of 600km x 900km and 400km x 700km respectively.
The following tables show the size in megabytes of tiles of Strategi® data. For NTF format, 3 figures are given: the average size of a data tile, the maximum size of a data tile, and the total number of megabytes for complete coverage of Great Britain. For DXF the figures represent the sizes of GBNORTH, GBSOUTH and complete coverage of Great Britain.
| Ground area covered | Source Scale | GBNORTH (Mb) |
GBSOUTH (Mb) |
Great Britain (Mb) |
|---|---|---|---|---|
| 600 km x 900 km 400 km x 700 km |
1:250,000 | 60 | 63 | 123 |
| Ground area covered | Source Scale | GBNORTH (Mb) |
GBSOUTH (Mb) |
Great Britain (Mb) |
|---|---|---|---|---|
| 600 km x 900 km 400 km x 700 km |
1:250,000 | 256 | 290 | 546 |
| Ground area covered | Source Scale | GBNORTH (Mb) |
GBSOUTH (Mb) |
|---|---|---|---|
| 600 km x 900 km 400 km x 700 km |
1:250,000 | 22 MB (compressed) 604 MB (uncompressed) | 28 MB (compressed) 816 MB (uncompressed) |
| Ground area covered | Source Scale | GBNORTH (Mb) |
GBSOUTH (Mb) |
|---|---|---|---|
| 600 km x 900 km 400 km x 700 km |
1:250,000 | 10 MB (compressed) 86 MB (uncompressed) | 13 MB (compressed) 122 MB (uncompressed) |
Meridian™ 2 tile structure
Meridian™ 2 tiles cover 10km x 10km. A tile name consist of the two letter National Grid code describing a 100km x 100km square followed by two digits, indicating the bottom left hand part of the 10km x 10km tile.
Examples of Meridian™ tile names are SX37, TR05, NJ56, HP60.
The following table shows the size in megabytes of tiles of Meridian™; in both NTF and DXF format. For each format, 3 figures are given: the average size of a data tile, the maximum size of a data tile, and the total number of megabytes for complete coverage of Great Britain.
| Ground area covered per tile |
Source scale | NTF (Mb) | DXF (Mb) | ||||
|---|---|---|---|---|---|---|---|
| Average | Maximum | Great Britain |
Average | Maximum | Great Britain |
||
| 10 km x 10 km | 1:50,000 | 0.15 | 3.3 | 447 | 0.36 | 7.0 | 1,054 |
Land-Form PANORAMA™ tile structure
Land-Form PANORAMA™ tiles cover 20km x 20km. A tile name consist of the two letter National Grid code describing a 100km x 100km square followed by two even digits, indicating the bottom left hand part of the 20km x 20km tile. For example, the tile called SN02 contains data for 4 different grid squares, each 10km x 10km: SN02, SN12, SN03, SN13.
Examples of Land-Form PANORAMA™ tile names are SN02, TL86, NJ40, HY22.
The following table shows the size in megabytes of contour tiles of Land-Form PANORAMA™ in both NTF and DXF format. For each format, 2 figures are given: the average size of a data tile and the maximum size of a data tile.
| Ground area covered per tile |
Source scale | NTF (Mb) | DXF (Mb) | ||
|---|---|---|---|---|---|
| Average | Maximum | Average | Maximum | ||
| 20 km x 20 km | 1:50,000 | 1.5 | 4.5 | 11.8 | 36.0 |
The following table shows the size in megabytes of Digital Terrain Model (DTM) tiles of Land-Form PANORAMA™ in both NTF and DXF format. For each format, 2 figures are given: the average size of a data tile and the maximum size of a data tile.
| Ground area covered per tile |
Source scale | NTF (Mb) | DXF (Mb) | ||
|---|---|---|---|---|---|
| Average | Maximum | Average | Maximum | ||
| 20 km x 20 km | 1:50,000 | 0.75 | 0.75 | 11.8 | 11.8 |
Land-Form PROFILE™ tile structure
Land-Form PROFILE™ tiles cover 5km x 5km. A tile name consist of the two letter National Grid code describing a 100km x 100km square followed by two even digits indicating the bottom left hand part of the 10km x 10km tile. The final two letters represent quadrants of the original 10km x 10km tile from which each of the four 5km x 5km tiles was derived. These quadrants are designated as NE, NW, SE or SW. For example, a 10km x 10km tile called SN02 contains four 5km x 5km tiles: SN02NE, SN02NW, SN02SE, SN02SW.
Examples of Land-Form PROFILE™ tile names are SN02NE, HP60SW, NN79SE, SK66SW.
The following table shows the size in megabytes of contour tiles of Land-Form PROFILE™ in NTF format. For each format, 2 figures are given: the average size of a data tile and the maximum size of a data tile.
| Ground area covered per tile |
Source scale | NTF (Mb) | |
|---|---|---|---|
| Average | Maximum | ||
| 5 km x 5 km | 1:10,000 | 1.2 | 99.9 |
The following table shows the size in megabytes of Digital Terrain Model (DTM) tiles of Land-Form PROFILE™ in NTF format. For each format, 2 figures are given: the average size of a data tile and the maximum size of a data tile.
| Ground area covered per tile |
Source scale | NTF (Mb) | |
|---|---|---|---|
| Average | Maximum | ||
| 5 km x 5 km | 1:10,000 | 1.4 | 1.4 |
1:10,000 Colour Raster tile structure
The 1:10,000 Colour Raster shares the same tile structure as Land-Form PROFILE™. A tile name consist of the two letter National Grid code describing a 100km x 100km square followed by two even digits indicating the bottom left hand part of the 10km x 10km tile. The final two letters represent quadrants of the original 10km x 10km tile from which each of the four 5km x 5km tiles was derived. These quadrants are designated as NE, NW, SE or SW. For example, a 10km x 10km tile called SN02 contains four 5km x 5km tiles: SN02NE, SN02NW, SN02SE, SN02SW.
Examples of 1:10,000 Colour Raster tile names are SN02NE, HP60SW, NN79SE, SK66SW.
Unlike the other products the 1:10,000 Colour Raster is a raster, not a vector product and is therefore supplied in an uncompressed 8 bit (256 colours) TIF™ format.
The following table shows the size in megabytes of tiles of the 1:10,000 Colour Raster in TIF format. The table shows the uncompressed size of each tile and the total number of megabytes for complete coverage of Great Britain.
| Ground area covered per tile |
Source scale | TIF (Mb) | |
|---|---|---|---|
| Per tile | Great Britain | ||
| 5 km x 5 km | 1:10,000 | 60 | 634,080 |
1:25,000 Colour Raster tile structure
The 1:25,000 Colour Raster shares the same tile structure as Meridian™. Each tile covers 10km x 10km. A tile name consists of the two letter National Grid code describing a 100km x 100km square followed by two even digits, indicating the bottom left hand part of the 10km x 10km tile. For example the tile called NS66 contains data for 4 different grid squares, each 10km x 10km: NS66, NS76, NS67, NS77.
Examples of 1:25,000 Colour Raster tile names are NT26, TR02, SN48, HY22. 1:25,000 Colour Raster tile names are identical to Land-Form PANORAMATM tile names.
Unlike the other products the 1:25,000 Colour Raster is a raster, not a vector product and is therefore supplied in an uncompressed 8 bit (256 colours) TIFTM format.
The following table shows the size in megabytes of tiles of the 1:25,000 Colour Raster in TIF format. The table shows the uncompressed size of each tile and the total number of megabytes for complete coverage of Great Britain.
| Ground area covered per tile |
Source scale | TIF (Mb) | |
|---|---|---|---|
| Per tile | Great Britain | ||
| 10 km x 10 km | 1:25,000 | 60 | 171,360 |
1:50,000 Colour Raster tile structure
The 1:50,000 Colour Raster shares the same tile structure as Land-Form PANORAMA™. Each tile covers 20km x 20km. A tile name consists of the two letter National Grid code describing a 100km x 100km square followed by two even digits, indicating the bottom left hand part of the 20km x 20km tile. For example the tile called NS66 contains data for 4 different grid squares, each 10km x 10km: NS66, NS76, NS67, NS77.
Examples of 1:50,000 Colour Raster tile names are NT26, TR02, SN48, HY22. 1:50,000 Colour Raster tile names are identical to Land-Form PANORAMATM tile names.
Unlike the other products the 1:50,000 Colour Raster is a raster, not a vector product and is therefore supplied in an uncompressed 8 bit (256 colours) TIFTM format.
The following table shows the size in megabytes of tiles of the 1:50,000 Colour Raster in TIF format. The table shows the uncompressed size of each tile and the total number of megabytes for complete coverage of Great Britain.
| Ground area covered per tile |
Source scale | TIF (Mb) | |
|---|---|---|---|
| Per tile | Great Britain | ||
| 20 km x 20 km | 1:50,000 | 16 | 12,992 |
Contact us at: edina@ed.ac.uk
EDINA, Causewayside House
160 Causewayside, Edinburgh
United Kingdom EH9 1PR
EDINA is the Jisc-designated national data centre at the University of Edinburgh.
