Single-frequency method simulation for determination of vertical ionospheric signal delay

The actual problem of recent global navigation satellite systems is increasing of positioning accuracy. This problem has several solutions. The first one is decreasing of pseudorange measurements error. The significant contribution in the budget of the pseudorange error is signal delay in the ionosphere. The contribution of the ionospheric error could be 60 percent of this budget. Therefore, the ionospheric error exception will have resulted in significant increasing of positioning accuracy. The research subject is a single-frequency method of determining the vertical signal delay in the ionosphere. The purpose of work is verification the method on model data. Single-frequency method verification was performed using simulation modeling. The article considers existing approaches for determining signal delay in the ionosphere. The dual-frequency method contains the systematic error due to satellite and receiver hardware delays. Dual-frequency phase method usage requires phase ambiguity resolution. Standard single-frequency method uses direct measurements of code and phase pseudorange, and respectively has limited precision as well as dual-frequency methods described above. The solution of this problem is usage of measurement first differences instead of direct measurements. This approach is realized in the one-frequency method based on code and phase measurement first differences. The article gives a detailed description of this method and the results of the simulation. Simulation results has confirmed efficiently of this method and allows starting experimental researches.