Study Of Signal Processing And Target Location In Bistatic Ground-wave Over The Horizon Radar

Combining with some key pre-research project in China, the problem of the signal processing and target location in coast-ship bistatic HF radar on moving platform is studied in this dissertation.Firstly, the principle and basic signal processing flow of this radar are introduced, and what follows is the choice of antenna unit and the design of transmit antenna array. Then, Uniform Planar Array (UPA) and Non-uniform Planar Array (NUPA) are also discussed as two type of transmit array of ground wave radar. Because of the modulation band width is narrow than the band width of other radar, the range resolution is much worse. Through analysis the problem of existing target location accuracy in practical field experiment, we conduct mathematical analysis according to the geometric relation of bistatic radar and conclude that the error of range sum is the main error source under short baseline while the azimuth error of target is also another main error source under long baseline. Furthermore, we analysis the accuracy of all possible measurement set that can be used to determine the position of target. Based on all above that we analysis, the novel methods of promoting accuracy of location , namely, methods of Geometric Centre of estimated points (GC) and Weighted Mean (WM) under T/R-R mode are presented. That is, the measurement subsets of (RT,θT)and(R, L, RT) are all used. The two methods can be used to not only improve the accuracy of finding but also determine the position of target in baseline. Moreover, computer simulations are conducted to show the efficiency of the new approaches discussed.