The statistic characteristics of HF Oblique Sounding Channel at mid and low latitude during ionospheric disturbance time

In this study, historical data MOFF from two HF propagation paths: Qingdao-Lanzhou and Guangzhou-Haikou at mid and low latitude, the midpoint referenced data are from two ionosondes located at Xinxiang and Guangzhou, respectively. They are used to study the disturbance dMOFF properties reflected by the ionosphere during the ionospheric disturbance period, and compared with the variation of dMUF calculated by ITU-R P.533. The relative variation dfoF2 in the midpoint is used an indicator to denote the ionospheric disturbance magnitude. It is found that the change trends of dMOFF, dfoF2 and dMUF are similar to each other during the ionospheric disturbance time.