Research on sites´ structure of HF air-to-ground communications

With the methods of geometry, sites´ structure of HF air-to-ground communications and the sites-setting methods are studied. It is intent on putting forward ways and means to allocate sites of HF air-to-ground communications efficiently. After proving the theory that coverage efficiency of circles with the same radius is higher than the coverage efficiency of circles with different radiuses, the optimal structure of two circles and multi circles are given. Via establishing the circle coverage model of fixed sites-setting, proves that the coverage efficiency is the highest when the centers of circles form a hexagon. Then the algorithm of calculating the sites´ coordinates and calculating the minimum circles are presented. According to the simulations, the algorithm´s feasibility and efficiency are validated.