Non-trible GPS receivers and virtual reference stations (VRS)

Abstract

The Virtual Reference Station (VRS) concept is revolutionising the work of surveyors and other professionals who require positioning data. Accuracy levels in the centimetre range that were made possible through real-time kinematic (RTK) GPS are now achievable using the VRS mode of surveying. At present there is limited information available on how well different GPS manufacturers receivers work using VRS. This research provides an insight into the VRS performance capabilities of popular GPS receivers on the market. The past few years has seen many countries install permanent reference station networks to spatially model the biases for a given region. The Department of Natural Resources and Water (NRW) in South East Queensland has developed a network of permanent reference stations called SunPOZ. SunPOZ operates using Trimble’s VRS software and hardware. The aim of this research project was to evaluate the precision, accuracy, reliability and performance of non-Trimble GPS receivers with regard to the SunPOZ VRS network. Leica, Thales and Topcon GPS receivers have been utilized in the research. The research results have confirmed that non-Trimble GPS receivers can operate within the VRS network. The results indicate that the receivers assessed are reliable, and produce similar precision levels and initialisation times to previous testing. The receivers performed well within the network of reference stations and provided results that should give greater confidence in the use of the VRS technique for precise point positioning.