Research On Passive Beacon Correcting Method Of OTH Radar

Over-the-horizon radar works in HF band, and can detect aircrafts and ships that are very far with the refraction of the ionosphere. Its ability cannot be limited by the earth's curvature, so the detecting range is far, the detecting region is large, but the detecting accuracy is low. Because of this, improving the accuracy is one of the main problems in OTHR. Presently, using beacon is one of the effective methods to improve accuracy, and passive beacons take more and more attention because of its advantages that passive beacons distribute widely and its geographical positions are known and fixed.Firstly, radio wave propagation and over-the-horizon radar theory has been described in detail. The location method has also been discussed.Secondly, the main factors of influencing OTHR's accuracy are analysed, which include the error of the ionosphere's parameters, beam bias and resolution of OTHR itself. Then it is analysed on further that the error of the ionosphere's height and its slanting angle can influence how much about the range and the azimuth of its detecting.Finally, locating method based on airport identification has been proposed. The takeoff and land-off of aircrafts has been identified for correcting the accuracy of target location. The method has possible to extend to other beacons.