A local tie survey is performed by Spatial Services for each Continuously Operating Reference Station (CORS) installation to provide 'local' GDA94(1997) horizontal coordinates and 'local' AHD71 heights to CORSnet-NSW users.
These surveys are performed by Spatial Services geodetic surveyors using best practice static Global Navigation Satellite System (GNSS) techniques.
High-quality local survey control marks are used and processed within a 3D network adjustment to provide connections to the existing ground control network.
Local tie surveys also provide the crucial link from our CORS to the surrounding ground control network in the national GDA2020 adjustment.
GDA94(1997) and GDA2020 coordinates are available from SCIMS Online.