1:250 000 Scale Colour Raster Technical Specification

This technical specification provides detailed technical information about 1:250 000 Scale Colour Raster. It is targeted at technical users and software developers.

1:250 000 Scale Colour Raster product specification

Number of tiles in Great Bitain

56 (edge matched)

Tile size

100km by 100km

Coverage

Great Britain

Availability

National coverage (in a single download)

Resolution

254 dots per inch (dpi)

Data structure

Raster

Storage volumes (GB coverage)

128 MB (compressed)

130 MB (uncompressed)

Update frequency

Quarterly: Annually (June)

Product legend

Maintained versions (in English and Welsh) of the 1:250 000 Scale Colour Raster legend, which defines all of the map symbols used in the product, can be found on the 1:250 000 Scale Colour Raster Downloads page.

Gazetteer

The 1:250 000 Scale Gazetteer includes approximately 25 500 points that cover the extent of the 56 100km by 100km tiles. The information is provided as a single file in ASCII text format and is included in the compressed download file.

Additional technical information

Additional information, common to all colour raster map products is available through the Colour Raster Map Core principle pages. These pages provide an overview of the product and a technical specification covering:

• Georeferencing

• Image file directory (TIFF)

• Product glossary