Positioning performance analysis using RWLS algorithm based on variance estimation methods

GPS is a navigation system that allows users to calculate their position in every desirable point on earth, sea or air as well as space. By increasing the velocity of receiver, the positioning accuracy will decrease; while it is very important to calculate the position of high velocity moving objects such as planes or ultra-high velocity moving objects like satellites. In this paper, seven methods for dynamic positioning, using recursive least squares method with pseudo-range and carrier phase measurements combined with the variance estimation methods for weighting observations are presented. Simulation results on data with different velocities from 100 m/s to 7300 m/s show that proposed methods reduce the positioning errors at high velocities by more than 50% compared to the RLS method.