Ordnance Survey
Ordnance Survey produces digital and paper maps and OS MasterMap for business, leisure, government and education, with quality Crown copyright maps of Great Britain.
http://www.ordnancesurvey.co.uk/

Ordnance Survey Ireland
The Irish national mapping agency.
http://www.osi.ie/

USA Environmental, Inc.
Ordnance and Explosives (OE) services including Unexploded Ordnance (UXO).
http://www.usatampa.com

ORDATA online
A US government sponsored database of world landmines and unexploded ordnance. Includes photographs, diagrams and specifications of various items of ordnance.
http://ordatamines.maic.jmu.edu/

UXB International, Inc.
Products, services and solutions to UXO, demilitarization, and hazardous materials problems across the world by UXB International, Inc.
http://www.uxb.com/

Ordnance Survey of Northern Ireland Home Page
Maps ,dems and data of Northern Ireland.
http://www.osni.gov.uk/

Ordnance Survey Britain's National Mapping Agency
Ordnance Survey produces digital and paper maps and OS MasterMap for business, leisure, government and education, with quality Crown copyright maps of Great Britain.
http://www.ordnancesurvey.com

The National GPS Network
This website is an essential resource for the precise Global Positioning System (GPS) user in Great Britain.
http://www.gps.gov.uk/

Cadastral Survey Reference Page
Cadastral Survey Information for the Land Surveyor involved in the survey and retracement of the Public Land Survey System
http://www.cadastral.com/

Merrett Survey Partnership
Worldwide land survey, topographic, geomatic, hydrographic, GPS and GIS data collection survey services.
http://www.merrettsurvey.co.uk/