摘要
The ionosphere is composed of a large number of electrons and ions, which are produced by the photoionization effect of the solar radiation on the neutral atmosphere. The altitude range of ionosphere is about 60–1000 km and varies with local time and other factors （e.g., solar and geomagnetic activity）. Although the ionosphere varies over multiply timescales, the diurnal variation is in the dominant position due to the sun’s photoionization effect.
The ionosphere is composed of a large number of electrons and ions, which are produced by the photoionization effect of the solar radiation on the neutral atmosphere. The altitude range of ionosphere is about 60–1000 km and varies with local time and other factors (e.g., solar and geomagnetic activity). Although the ionosphere varies over multiply timescales, the diurnal variation is in the dominant position due to the sun’s photoionization effect. Consequently, it is expected that the ionospheric electron density increases
