Minimum Solar Activity Period: Performance Improvement of the Relative Positioning

Abstract

In the relative positioning, even considering that part of the errors due to ionosphere is
canceled with the double-difference observations, strong ionospheric effects can occur
in maximum solar activity period. However, in minimum solar activity period, the
ionospheric effects decrease significantly and therefore an improvement of the relative
positioning performance takes place. In this paper we aim at showing that
improvement for the scientific and GPS community users. So, have been experiments
by using GPS data of two stations of the Brazilian Network for Continuous Monitoring
of GPS, forming a baseline of 430 km. The processing were use accomplished with
interval of two hours, and only L1 carrier data have been used. The analysis of the
obtained results has been carried out from the discrepancies between the “true”
coordinates and corresponding ones obtained in the processing. In maximum solar
activity period the discrepancy value reached 25 m. On the other hand, in minimum
solar activity period, the discrepancy value reached 5,5 m. It is important to emphasize
that the majority of the discrepancy values didn’t exceed 0,50 m, and in some cases
only reached 0,10 m. This shows the increase of application possibilities of the relative
positioning using single-frequency GPS receivers in minimum solar activity period.