OS Net™ Ordnance Survey's RTK GPS Network

Mark Greaves

Geodetic Analyst, Ordnance Survey

7th May 2006

What is OS Net™?

National GPS infrastructure and

service developed by Ordnance

Survey to provide up to 1cm

accuracy real-time positioning

Enables positioning against OS

MasterMap® and supports

Digital National Framework

(DNF) principles

The Current OS Net Network

• 90 base stations in operation

• Density enables RTK positioning services across most of the country

OS Net structure

OS Net™Data Servers

(OS HQ)RTK for Ordnance Survey surveyors

via GPRS / GSM

Raw GPS data in RINEX format for

www.ordnancesurvey.co.uk/GPS

OS Net base station network

Accuracy of OS Net

All stations

Overall rmse:east: 11mm north: 16mm height: 31mm

Precision of OS Net

All stations

RTK initialisation time

All stations

What OS Net enables

Up to centimetric level positioning service for Ordnance Survey surveyors

Real-time, raw GPS data feed to OS Net partners to create commercial positioning products

Access to the national coordinate reference frame through free products from www.ordnancesurvey.co.uk/gps

Data to the Meteorological Office to aid their weather forecasting models and for some academic studies

Support to pilot studies in applications outside of agreed partner terms

OS Net benefits

Delivering efficiency and flexibility to Ordnance Survey

Supports local and national applications that require a positioning element

Enables quicker easier positioning

Supports interoperability of data and the use of a common coordinate system

Provides a revenue opportunity

Commercialisation through Partners

OS Net can bring significant efficiencies to any application that uses GPS

Initially entering high-accuracy markets where most benefit can be realised

Work to foster new market areas

Future direction of OS Net

Short term

• Strengthening network and possibly extending into north west Scotland

• Work with partners and policy developers to develop and position OS Net

Medium term

• Infrastructure will be renewed with dual GPS + Galileo receivers

• Galileo test bed in the south east. Aid internal and national understanding of what Galileo will bring

• Work towards the goal of ubiquitous survey quality positioning, through involvement in external projects and the development of OS Net

Summary

OS Net used internally by 130 field surveyors

Recent accuracy testing has shown 1-2cm horizontal accuracy, 3cm vertical accuracy

Partners are taking the raw data from OS Net to build commercial services

OS Net has the capability to support national policy initiates that require positioning

Expanding OS Net into the NW of Scotland is being considered

OS Net will be updated to support Galileo

Contact for further information

Customer Contact CentreOrdnance SurveyRomsey RoadSOUTHAMPTONUnited KingdomSO16 4GU

Phone: 08456 05 05 05

Fax: 023 8079 2615

Email: customerservices@ordnancesurvey.co.uk

Website: www.ordnancesurvey.co.uk