Determining the Initial Value of Carrier Phase Smoothing Pseudorange by Least Squares Straight Line Fitting Technique

In the two-way ranging system of the inter-satellite link, the pseudo-code tracking method is generally used to obtain the ranging accuracy. Because the carrier measurement accuracy is better than the pseudo code, the carrier phase smoothing pseudorange method can be used to further improve the pseudorange measurement accuracy. As for the smoothing method proposed by Hatch, the convergence time will be long when the initial error of the smooth pseudorange is large. To solve this problem, this paper presents a method to determine the initial value of smooth pseudorange using the least squares straight line fitting technique. The simulation analysis results show that the convergence time can be shortened to more than 200 symbols, and the ranging accuracy is with 0.3m, where there is no dynamic condition and the Eb/N0 is 4dB.