Welcome to <a href="http://smartnetaus.com/home/">smartnetaus</a>.com, here we help you build best RTK from CORS network. We successfully deal in services like agriculture, construction, surveying and GIS / DGNSS. Now you do need to spend extra cost in setting up your own reference station. The CORS network acts essentially as a continuous reference station within the entire network. The Driftnet CORS GPS Modem allows access real time RTK and DGPS network corrections without the use of a base station