| Security is an eternal topic,with the progress of science and technology,security technology has also made considerable progress.However,for small intrusion targets such as UAVs at low altitude and slow speed,the traditional security system has very limited monitoring range,and it is difficult to achieve the requirements of all-day,all-weather and low-falsealarm-rate detection.With the development of millimeter-wave devices,circuits and antenna technology,the application of millimeter-wave radar has also made great progress.Millimeter-wave radar is not affected by light and visibility.It has the ability to detect targets in all weather and all the time.It can be used in close-range area security.This paper focuses on the regional security millimeter-wave radar system,and studies the signal processing algorithm of the regional security millimeter-wave radar.The main work is as follows:1.To meet the requirement of multi-target high-precision detection of regional security millimeter-wave radar,a combined-wave FMCW multi-target detection algorithm is proposed.Firstly,the waveform of radar transmitting signal is designed,and the principle of target distance and velocity detection is deduced theoretically.Secondly,two target matching methods which can solve the ghosts are proposed.Then,the multi-target angle measurement method and CFAR detection method used in the algorithm are introduced.Finally,the concrete realization method of the combined waveform FMCW multi-target detection algorithm is given.The superiority of the algorithm is discussed theoretically,and the effectiveness of the algorithm is verified by simulation experiments.2.To meet the requirement of low altitude slow and small multi-target detection for regional security millimeter-wave radar,a multi-target detection algorithm based on zigzag-wave FMCW is proposed.Firstly,the principle of multi-target detection algorithm for zigzag-wave FMCW is deduced.Then,the problem of difficult targets detection under low SNR is solved by clutter suppression.Then an improved frequency estimation algorithm is proposed,which can maintain a relatively stable estimation accuracy under low SNR.The effectiveness of the improved frequency estimation algorithm is proved by comparative experiments.Finally,the flow chart of the detection algorithm is given,and the effectiveness of the multi-target detection algorithm is validated by simulation experiments under low SNR.3.Aiming at the problem of mode switching in the application scenario of regional security radar system,the adaptive target detection method is studied,and a parametric adaptive detection algorithm suitable for multiple radar modes in low SNR environment is proposed.Firstly,the anti-symmetric steering vector mismatch sensitive detector and the antisymmetric steering vector mismatch robust detector under low SNR are derived.Then,the parametric detectors suitable for radar scanning and tracking are obtained by parametric processing.The simulation results show that the proposed parametric adaptive detection algorithm has better detection performance than the existing methods under the condition of small training samples,and can also be applied to many application environments under the condition of steering vector mismatch. |
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