摘要： Upon the availability of fast and stable Internet access and the mature virtual reference station (VRS) technique, the network based real time kinematic RTK GPS technique, which overcomes the limitations of traditional RTK (single reference station) positioning, has become an important tool of survey engineering. Since 2004, a regional real time GPS network with 86 stations for expanding the effective range of cadastral measurement has been set up in Taiwan. Users can get VRS observations from the control centre via wireless Internet and acquire high quality positioning. In an experiment we conducted, we find that after applying proper coordinate transformation to the coordinates measured by network based RTK GPS positioning, three-dimensional coordinates with centimetre level accuracy can be achieved, with results for the horizontal direction generally better than the vertical direction. 出版者： Taylor & Francis 出版日期： 2012-01-01 出處： Survey review - Directorate of Overseas Surveys, 2012-01, Vol.44 (324), p.3-8 版權： 2012 Survey Review Ltd 2012 識別號： ISSN: 0039-6265 識別號： EISSN: 1752-2706 識別號： DOI: 10.1179/1752270611Y.0000000006
