Analysis of the relationship between the earthquake and the GPS positioning error

In recent years, it has been reported by many researchers that anomalies of the number of electrons in the ionosphere occur before earthquakes. Because the radio waves used for the global positioning system (GPS) propagate through the ionosphere, it is expected that the anomalies of the ionosphere causes fluctuations of the propagation path and propagation delay, and they result in positioning errors. Therefore, we attempt to predict earthquakes using the GPS positioning errors. In this paper, we discuss the relationship between the GPS positioning errors and earthquakes based on a statistical analysis using the data observed for more than one year.