عنوان مقاله [English]
نویسنده [English]چکیده [English]
During the history, war has been related with development of technology directly. By the erly of 21th century, the century that identifies by “communication and information era”, development of communication and information technologies has changed the nature of war. In this circomestanses appearance of new methods against air threat, appearance and role of the new radars with advanced technology is undeniable. Today as long range target detectors, over the horizon radars in HF band with electromagnetic wave dispersion ability to space and use of wave reflection character of ionosphere in compare with line of sight radars have regarded for applying by developed countries.This essay had tried to research on reason of application and effective factors in over the horizon HF radars working. The reason of apply, comparison of target detection and feature of these radars with ordinary line of sight one will explain completely. Therefore we will introduce main factors of O.T.H radar’s structure (receiver, transmitter, antenna and data processor) and finally after proposal management of radar, ionosphere layers and loss of energy will get logical conclusion.