The z propagation hole in the ionosphere

摘要: Abstract The occurrence of F -region triple-splitting allows us to examine experimentally the properties an unusual propagation hole in ionosphere. Two methods estimating angular size are discussed. first is based on beam effect Z echoes, according which echoes returned ground a narrow beam. second follows from analysis distribution angle arrival echoes. It found at Hobart that, with wave frequency 4.65 Mc/s, approximately circular width half-power points less than 0.84°. Under certain circumstances provides means by waves can pass completely through otherwise reflecting ionospheric layer.