Positioning technology support

If you're a surveyor or working with infrastructure, make the most of your investment in GNSS positioning technology with our online tools.

Whether you're looking for Rinex data, benchmarks or transformations between coordinate reference systems, you'll find them all here. Also check out our guide to coordinate systems in Great Britain.

OS Net online tools

OS Net RINEX data
Find stations and request data.

OS Net Rinex data batch search
Find the nearest active stations to a batch of coordinates.

Coordinate transformation tool
Transform coordinates from ETRS89 TO OSGB36 National Grid and vice versa.

Passive stations
Search our database of some 900 passive GPS stations in Great Britain.

Search by coordinate or grid reference for OS survey marks around the country which were made to record height above Ordnance Datum.

Height levelling datum
Learn about the Liverpool and Newlyn geodetic levellings in the 1840s, 1910s and 1950s, then find the correction that should be applied to spot heights readings, depending on the location in Great Britain.

Triangulation stations
Find where triangulation stations are located, Search by coordinates, OS Landranger Map sheet number and more.

OS Net information

OS Net accuracy
Find out just how accurate OS Net is, expressed as standard error distances in metres.

Antenna phase centre offsets
A GPS baseline is measured between the phase centres of two antennae. Find out the various antennae and offsets currently used in the active network.

Spreadsheet for coordinate calculations
Our coordinate calculations spreadsheet enables you to carry out common calculations with coordinates. It includes a full set of Transverse Mercator projection functions.

A guide to coordinate systems in Great Britain (PDF)
Learn about the concepts of coordinate systems to help you use coordinate data and mapping coordinate systems in Great Britain.

Understanding the meaning of technical terms relating to OS Net and global navigation satellite systems.

Grid InQuestII coordinate transformations software
Grid InQuestII transforms between the ETRS89 (WGS84) and OSGB36 National Grid coordinate systems using the same transformation models (OSTN15/OSGM15) as the online coordinate transformer.

OSTN15 and OSGM15 for Developers
We are pleased to make OSGM15 and the OSTN15 available to software developers for incorporation into their software.  This includes transformation in Ireland and Northern Ireland and also OSTN15 in NTv2 format which is more compatible with GIS systems.

Local levelling data
Our full list of all the known local levelling datums in Great Britain. Newlyn and Liverpool are two of them.

OS Net and GNSS
A comprehensive FAQ for expert navigation data users.

GPS information

Using GPS with OS maps
GPS and Ordnance Survey maps use different models for the earth and coordinate systems. Learn about the problems this can cause and how to overcome them.

Sat nav and GPS devices FAQ
Questions asked by the publc about in-vehicle sat navs and the issues they can cause.