Mark Greaves is Ordnance Survey Lead Consultant for Geodesy. He holds an MSc (with Distinction) in Engineering Surveying and Geodesy from the Institute of Engineering Surveying & Space Geodesy at Nottingham University and is a member of the RICS. Mark specialises in geodetic GNSS computations and analysis, coordinate reference system realisation and datum transformations. He has been in the team responsible for managing and developing the OS Net GNSS network since its inception.