The Study On The Moving Target Echo Simulation And Localization In Passive Radar System

With the increasingly serious four-anti threats for radar reconnaissance in the modern electronic warfare, the passive radar attracts widespread concern and research for its advantages such as good invisibility, strong anti-strike capability and a wide range of reconnaissance. It has important implications for the use of computer modeling technology to simulate the dynamic target echo signal, to validate arithmetic and analyze target’s characteristic.Regarding to the echo simulation of the passive radar system, In this paper, First, there is a comparison and analysis on the system structure between the passive radar and normal bistatic radar, and in the same time, some performances of opportunity illuminators are investigated which can be a reference when choosing opportunity illuminators for passive radar.The FM broadcast signals are used as transmit signal in this article, the aircraft can be considered to be a point target when the transmit signal is FM signal. The most important factor in the point model is the target complex radar cross section.In order to acquire more accurate static RCS database, the computer-aided modeling and electromagnetic calculation software are used. After the ballistic trajectory of midcourse simulated and the azimuth angle of target in flight calculated, the dynamic characteristics of RCS of the target under the given background obtained.An accurate approach to power budget analysis between the direct signal and the scatter signal for passive radar is presented, regarding to the FM antenna is near to the ground, beside the free space propagation model, the TRP model is introduced. What’s more, based on the point target signal model, the research on the characteristics of the target time delay, Doppler shift and complex radar cross section change with the time.At last, this paper presents analysis and comparison on the methods of moving target detection of passive radar, a novel method for moving target detection of Passive Radar is introduced. Regarding to the high-speed and accelerating target, the result of the Doppler analysis method is seriously affected by Doppler frequency migration. In order to solve this problem, a target detection algorithm based on the Doppler analysis and fractional Fourier transform is proposed, with this algorithm the velocity of the moving target and accelerating speed can be well predicted. This algorithm well improved the performance of Doppler analysis. It is able to improve the detection performance of a high-speed and accelerating target. Simulation results are presented to verify the effectiveness of the proposed method.