RTK Coverage

GSM Reference Networks

The Snap In RTK modules GSM modem incorporates NTRIP capability (Network Transport of RTCM via Internet Protocol) which lets you tap into existing reference networks via mobile phone connection (depending upon local availability). Often know as “Network RTK”. The in built GSM modem works with a wide range of the UK’s mobile phone networks both contract and pay as you go, so you can choose the network that gives you the best reception in your area.

The Snap in RTK module combined with a TopNET+ subscription gives a mobile RTK solution without the cost and operational area logistics of a fixed base solution or the need to transport and setup a mobile RTK base. All that is required is a stable mobile phone signal to maintain RTK accuracy.

TopNET+ is TopCon GB’s dedicated GNSS network correction service, available to all subscribers using a GNSS receiver unit and a mobile data connection. It offers users a high accuracy RTK grade level accuracy, utilising the Ordnance Surveys nationwide CORS (Continuously Operating Reference Stations) network. Utilising both GPS and GLONASS throughout the UK and Ireland.


  • 2cm repeatable position accuracy
  • GPS + GLONASS satellite reception
  • No need for an RTK base station
  • 24/7 operation and nationwide coverage*
  • Compatible with UK GSM/GPRS & EDGE networks
  • 3, 6, or 12 month TopNET subscriptions