Summary statistics for these two stations are listed in Table 1. From these results,
the accuracy of the VRS RTK positioning is generally better than 3 cm in horizontal position, while the height accuracy is in the range of 1–5 cm. As expected, the standard deviation
in the horizontal position is a factor of 2 to 3 times better than that in height.
These results have proven that VRS RTK positioning based on a multiple-reference-station network is an effective GPS positioning method for centimeter-level surveys,
even under the unfavorable ionospheric conditions in Singapore.