Real-Time Kinematic surveys with the Global Positioning System (RTK GPS) have been used for a variety of different surveying applications. It’s use in cadastral surveying is commonplace in all registered surveying applications in Victoria. As of July 1st, 2022 except those registered surveys supporting partial survey subdivisions and Records of having re-established a cadastral boundary must connect to MGA2020 and using RTK GPS is an excellent method to achieve this. GPS is also being used commonly for large detail and contour surveys as well as for a variety of construction engineering applications.
RTK GPS techniques have become more reliable, cheaper and productive with ongoing research and development which make this technique more attractive for a range of surveying applications. Until the mid-1990s, post-processing of the GPS data was the only method available to determine survey-grade positions. A new method was introduced, namely Real Time Kinematic (RTK), with the advancement of the GPS technology. RTK GPS is a technique where the carrier phase measurements of a reference station are sent via a data link to a rover receiver in the field. Together with its own measurements the rover calculates its position in real-time with an accuracy at the centimetre level. RTK is a tool for real-time positioning with an accuracy of about 2 cm for horizontal and 4 cm for vertical positions. However, by connecting to a known ‘base station’ point localized to the project can greatly improve the accuracy of the measurements down to sub centimetre.
There are two primary survey tasks for which RTK systems are used. One application is the precise positioning of existing features (topography, mapping, and as-built surveys). Another powerful application of RTK is navigating to features with known coordinates. This is done when recovering boundary marks or while transferring design features that exist electronically to marks in the ground (setting out in construction).