Combined analysis of real-time kinematic GPS equipment and its users for height determination

Ellipsoidal and Australian Height Datum heights have been determined for a 60-point control network from five base stations by three separate users using three different makes of real-time kinematic (RTK) global positioning system (GPS) equipment. This was to determine whether these RTK GPS surveys (i.e. equipment and users combined) can meet vertical accuracy specifications for contract work with Main Roads Western Australia. A comparison of the differences between the RTK GPS ellipsoidal heights and the control indicates 51 mm (95% confidence) accuracy, accounting for errors in the control network. Likewise. the difference between the RTK GPS-derived Australian Height Datum heights and the control indicates 53 mm (95% confidence) accuracy. However, there was an increasing number of failed RTK GPS position solutions with increasing baseline length, which had to be omitted from these statistics.