Improved triple difference GPS carrier phase for RTK-GPS positioning

摘要

This paper will develop a new Global Positioning System (GPS) mono-frequency triple difference positioning technique. Initially presented in [1], this filter propose to use the carrier phase time-difference measurements as measurements. We use only the carrier phase measurements to free from multi-path effects on pseudo-ranges (typically in urban environment). This technique is an alternative to the floating ambiguity DGPS positioning [2] [3]. The difference is that, in triple-difference filtering, we do not estimate the carrier phase ambiguities terms and we deal with a classical colored Kalman filter. Similar technique has been used in [1]. The main difference between their filter and our is, first, the noise modelisation (in our case the triple difference carrier phase noise is not considered as a brownian), and, secondly, our filter deal with classical correlated noises (we are not using delayed state observation model). We will apply the new filter on real dataset, and show that sub-decimetric noisy positioning is reached using this technique. Finally we will compare the results to ones obtained with classical Real Time Kinematic (RTK) positioning.