Ordnance Survey – Great Britain's national mapping agency

GPS and Positioning Services

This website is an essential resource for the precise Global Positioning System (GPS) user in Great Britain. It also contains useful information for ALL users of GPS, both recreational and professional.

The 2nd edition of "Guidelines for the use of GNSS in Surveying and Mapping" has just been released and can be downloaded from the Royal Institution of Chartered Surveyors (RICS) communities website

Commercial services


Real-time and high frequency GPS correction services

Ordnance Survey operates a network of more than 100 continuously operating GPS receivers - OS Net.

Ordnance Survey is working with partner organisations to utilise the GPS data from this network to develop and provide a basket of real-time and post-process GPS correction services, with a choice of accuracy levels available to customers in a wide variety of markets.

Information pages

For beginners and professionals alike. A valuable source of information on GPS, coordinate systems, projections and more.

Ordnance Survey Geodesy and Positioning - the view to 2012

Document setting out the four year strategy for the development of geodesy and positioning within Ordnance Survey.

Free services

SurveyingOS Net RINEX data server
Raw GPS data in the RINEX format is available for the last 30 days from over 100 OS Net stations, positioned in the European standard coordinate system ETRS89. The quality of your GPS data and resulting positions is significantly improved when combined with this RINEX data during post processing.
Please see OS Net partners for more links to positioning services and systems.


Coordinate transformer 
Want to transform your GPS positions to Ordnance Survey National Grid or height, or vice versa? The coordinate transformer utilises our precise coordinate transformations OSTN02 and OSGM02 which can be used online or downloaded.


Legacy Control Databases

A free online resource, providing all of the Ordnance Survey traditional horizontal and vertical control survey information, from Trigs and benchmarks to passive GPS stations, is now available.


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