Method for calculating Es field strength of HF bands in summer

Sporadic E (Es) is the irregular structure of ionosphere occurred in the layer E sporadically and its influence is very important to shortwave communication, and Es is of frequency occurrence in China, Using the f_oEs data of the ionospheric vertical detection network in China, the spatial variation of occurrence of f_oEs and its influence on the short wave communication are analyzed. The short wave reception level is closely related to Es and F-layer reflection, which is the result of their joint action. In summer, the Es layer generally improves the maximum using frequency of the shortwave link, widens the available frequency band and improved signal quality. Based on the ionospheric f_oEs data at the intermediate point of the short wave link, the propagation model of Es is constructed to predict the received level during the happen of Es. The prediction values are compared with the observed values of the shortwave link from Xi’an to Qingdao and Xi’an to Kunming. The results show that through receiving the signal of 5 MHz, 10 MHz and 15 MHz operator frequency transmitted by national time service center, and the predicted values are corresponding to the measured values, which reflects the trend of the measured received level.