Drift Velocity Estimation of Ionospheric Bubbles Using GNSS Observations

Abstract

Equatorial plasma bubble (EPB) irregularities are large-scale plasma depleted structures that exist in the equatorial and low-latitude ionosphere. Thus, particularly in these regions, much attention must be given to the effects of the EPBs in the life critical applications based on global navigation satellite systems (GNSS). The study on the dynamics of plasma bubbles, particularly in the determination of their drift velocities, and their impact on ground-based augmentation system is of fundamental importance for civilian aviation. In this regard, we proposed a methodology to estimate the zonal drift velocities of the plasma bubble irregularities using slant total electron content (TEC) measurements derived from two spaced ground-based GNSS receivers. The experiments were performed with the purpose to evaluate if the drift velocities obtained using the methodology proposed in this study agree with the velocities deduced from all-sky imaging systems. The results revealed that the TEC-estimated mean eastward drift velocities were comparable with the values deduced from the airglow techniques, and with the results obtained from previous studies. Therefore, the methodology proposed in this work to infer the plasma bubble drift velocities seem to have the potential in future investigations to provide a new data source in this field.