Algorithm and Application of the Iterative Running Mean Filter on the Pseudo-Range Differential Positioning Based on the Smartphone GNSS Observations

The significant improvement of the performance of the modules of GNSS inside the smartphones, giving a great promotion of precise applications at the mass market. Considering the instability of GNSS carrier phase from the smart phones in urban environment, the pseudo-range is still the main source of the GNSS positioning when the carrier phase is greatly disturbed. Therefore, it is of great practical significance to improve the accuracy and reliability of pseudo range positioning, particularly the pseudo-range differential positioning. Aiming at solving the problem that the pseudo-range differential positioning accuracy of smart phone is not enough for the precise navigation and positioning, we give a method of the iterative running mean filter algorithm. The precision and effectiveness of the proposed method were assessed through a practical test, and the test result show that the precision of the iterative running mean filter pseudo-range differential is equivalent to that of the carrier differential, which is at the sub-meter level. The algorithm has a simple structure that can be implemented easily, and the obvious precision improvement can be witnessed at the application of the double differential pseudo-range positioning. Hence, this method has great potential at the precise navigation and positioning application in the urban canyon in the case of great disturbance of the GNSS carrier observations.