MUF Variability at Haikou, China

Comparison of maximum usable frequency (MUF) variability over Peninsular Malaysia with IRI model during the rise of solar cycle 24

“…Seasonal consideration for 2009 shows the variability of the The MUF VR plots indicate that night MUF VR ranges are higher than those of the daytime except for MUF VR of test for 2011, and this is consistent with the findings in Chen et al (2008). At night, critical frequency for F2 layer, foF2 variability increases with decreasing solar activity.…”

“…where M(3000)F2 is the propagation factor of F2 layer of which its influence is significantly less than foF2 Fotiadis et al, 2004;Chen et al, 2008), and MUF(3000)F2 is a usable frequency that can be received at a distance of 3000 km when reflected by the ionosphere (Bradley, 1973;Adeniyi et al, 2003). The biggest problem in HF radio communication is the rapid change in the ionospheric characteristics, resulting in the need for the operating frequencies to be changed from time to time to get satisfactory performance (Lakshmi, 1994).…”

“…Studies on MUF variability include those of and Chen et al (2008) who investigated MUF variability in Europe such as Rome and Slough and low latitude stations, i.e. at Haikou, China respectively.…”

Short-Term Forecasting Method of Maximum Usable Frequency for HF Communication Based on Oblique Sounder

“…According to the mechanism, therefore, critical frequency can be determined by the junction frequency: Inversing foE and foF1 can be directly used equation ( 5) and (7). Considering the relation between F2 basic MUF and foF2 is much tighter than that of others, such as M(3000)F2 and f H [19], therefore, M(3000)F2 and f H of reference ionosphere model were recommended in the inversion, and reference ionosphere of China was recommended in China and its surrounding areas [18,20]. Under the condition of that, foF2 can be determined from equation ( 9) by finding the frequency in between 0 and 30MHz by 0.01MHz step, which deviation between two basic MUF of the forecast and observation is minimum.…”