Research On Crossover Accident Detection Technology Of Super - High - Speed Moving Target

Ultra high-speed aircrafts bring new challenges to radar target detection systems, The ultra high-speed moving of targets has a great impact on the echo signal.Firstly, there will be range migration in the echo signal.Secondly, the echo signal is not single-frequency, but a polynomial phase signal which will bring a time-varying Doppler frequency. These two points can seriously affect the effect of coherent integration and decrease the performance of traditional detection methods. This paper is based on ultra high-speed moving target and specifically studies on the accumulation and detection methods in the presence of range migration and time-varying Doppler frequency. The main work is as follows:1) An ultra high-speed moving targets echo model is established,and the paper verifies the impact of ultra-high-speed moving targets on the traditional method.Then the range migration and time-varying Doppler frequency resulted from ultra-fast target are analyzed,and a generally design for detection of ultra high-speed mo ing targets is proposed.2) For range migration, keystone transform is deeply studied, and the paper discusses three methods to implement keystone transform:sine interpolation algorithm, discrete Fourier transform algorithm and Chirp-Z transform algorithm. Theoretical analysis is given and the simulations prove that these three algorithms can effectively achieve the range migration correction. The improvement of radar detection performance after range migration correction is studied.3) The echo signal after range migration correction corrected is analyzed and the relationship between the time-varying Doppler frequency signal detection and Parameter estimation and detection of LFM signal is discussed. HAF, Dechirp, FRFT and WVD are applied to Doppler parameters estimation.The simulations prove that these algorithms can effectively improve the detection performance. Meanwhile, the computational cost and the detection performance of these several algorithms are simulated and compared.