Mitigation of Ionospheric Effects on GNSS Positioning at Low Latitudes

Abstract

Ionospheric conditions at low latitudes are extremely harsh due to the frequent occurrence ofscintillation and the presence of strong TEC gradients. For this study, the São Paulo state region in Brazil is chosenas a test area. This study presents a strategy to mitigate the ionospheric impact on RTK positioning with anexperimental result. The proposed strategy explores two approaches that can be applied simultaneously: a) tomitigate the scintillation effect on the GNSS signals by refining the stochastic model of the correspondingobservations and b) to precisely estimate the residual double difference ionospheric delay by exploiting an accurateTEC map.The strategy was tested on a long baseline kinematic processing under strong scintillation conditions (DOY21 in2014). Significant improvements were observed when the combined use of the two mitigation approaches describedabove was compared with the use of conventional state-of-the-art approaches. Copyright # 2017 Institute ofNavigation