An Improved Marine Multi-Constellation Pseudorange Single-Point Positioning Algorithm

In order to improve the navigation and positioning accuracy of the Beidou satellite navigation system (BDS) on the sea, an improved marine multi-constellation pseudo-range single-point positioning algorithm is proposed. The algorithm reduces the complexity of the counting process and improves the positioning accuracy on the basis of ensuring an optimal effect of satellite selection, which introduces satellite broadcast data quality and user equivalent distance error in the satellite selection algorithm. The dynamic improved multipath model on the sea is established to realize the optimization of dynamic positioning accuracy with combined BDS/GPS/Galileo in the marine environment. The results of data processing show that, the effect of the satellite selection is close to optimality. During the observation period, the average weighted position dilution of precision (PDOP) values of the combined system are both below 2 and the average value is 1.24, and then the positioning accuracy is greatly improved. The improved multipath model obviously weakens the multipath effect and further improves the positioning accuracy. The RMS of positioning error obtained by the improved algorithm is 4.48m in the horizontal direction and 6.78m in the elevation direction, which is 53% and 60% lower than that of the traditional BDS positioning.