Statistical characteristics of ionospheric phase fluctuations

Differential phase measurements of the 150- and 400-MHz coherent frequencies radiated by the U.S. Navy Navigation Satellites (TRANSIT) are used to determine the characteristics of the phase fluctuations, induced by ionospheric irregularities, on transionospheric propagated radio waves. The data analyzed were recorded at a midlatitude installation during a period when the geomagnetic planetary index, kp, ranged between 3 and 4. The ionospheric phase fluctuations are characterized in terms of statistical parameters and are presented as a function of analysis time interval, time of day, propagation angle and corrected geomagnetic latitude of the ionospheric irregularities. The phase fluctuations resulting from irregularities located within and north of the midlatitude trough are compared with the fluctuations associated with irregularities in the region south of the equatorward edge of the trough