Abstract
The single point positioning by single frequency receivers provides positioning results in real time. Its accuracy is about 10m. However, in non-real time usage, such as a fixed point observation, there is a possibility to improve the positioning accuracy of a single frequency receiver by using post interferometric processing. Two positioning experiments, the fixed point positioning experiment and the recorded trajectory comparison experiment of an object moving at a low speed between dual and single frequency GPS receivers, were carried out to examine the positioning accuracy of a single frequency observation and its post interferometric processing. The results of these experiments showed the positioning accuracy and repeatability were 0.09 to 0.12m and 0.02 to 0.07m respectively, in the measurements of the fixed point. And the differences of the recorded trajectories between the dual and the single frequency receivers were 0.65 and 1.18m and the standard deviations were 0.47 and 0.68m respectively, on the horizontal plane. These results suggest that the single frequency observation and its post interferometric processing using permanent GPS station data, has a sub meter positioning accuracy in the fixed point positioning and a repeatability on the horizontal plane of less than 1m on the recorded trajectory of an object moving at a low speed.
