Detecting the small-scale ionospheric irregularities based on GNSS data

Small-scale ionospheric disturbances can bring additional information about earthquakes and tsunami parameters. On the other hand such weak disturbances hardly can be detected by GNSS-TEC measurements. Being using of S4 and σφ indices we can count on reliable detecting of such events. However both of these indices do not have enough sensitivity too. We suppose that the second-order derivative of the GNSS signal phase is a high-sensitive parameter for the small-scale ionospheric disturbances detection. This report devotes to the problem of how to utilize the second-order derivative of the GNSS-signal phase as a sensitive mean to detect the weak small-scale ionospheric disturbances.