Design Of Integrated Microwave Doppler Bullet Velocity Measurement System

The technology of microwave Doppler velocimetry has been widely used in transportation,weaponry and shooting range testing,etc.However,the microwave velocimetry radar actually used in shooting range is generally not integrated and large in size,which makes it inconvenient to carry.Therefore,this paper focuses on the application requirements of high-integration missile velocity measurement radar.The details are as follows:1.Aiming at the problem that microwave Doppler velocimetry radar is generally large in size and complicated in layout in shooting range application,a set of compact microwave Doppler velocimetry system with perfect structure and capable of measuring multi-point velocity is built in this paper.A small 10.525 GHz constant frequency continuous wave radar is used as the sensor,and the signal processing algorithms such as static clutter suppression and time-frequency estimation of Doppler signal are completed by FPGA.Combined with the wide measurement range of the system,the corresponding sampling rate is adjusted according to the prior information of the target speed.In order to achieve multi-point velocity measurement of the target,the performance of three time-frequency estimation algorithms,namely Short-Time Fourier Transform(STFT),Wavelet transform(WT)and Wingner-Ville distribution(WVD),and the feasibility of hardware implementation are emphatically analyzed.Finally,the STFT is selected and the key parameters are selected.Aiming at the problem that the estimation accuracy decreases due to the fence effect in FFT spectrum estimation,through the analysis of the characteristics of interpolation correction algorithm,a combination of Rife and Quinn algorithm is proposed to improve the correction accuracy,and the noise simulation of each algorithm and the energy center of gravity method is carried out.The simulation results show that the proposed combination algorithm is better.2.Hardware circuit design and program design based on Verilog HDL are carried out for the designed signal processing scheme,and the hardware realization of signal processing algorithms such as variable sampling rate module,clutter suppression module and short-time Fourier transform module is completed.In addition,in order to save and read the original data,a data storage module and a reading interface are developed.Finally,the development of human-computer interaction interface is completed on the basis of serial screen.3.According to the characteristics that the designed system has a wide measurement range and can obtain multi-point velocity,a verification environment corresponding to its measurement requirements is built.The speed point acquisition and measurement accuracy verification experiments are carried out for the low speed range,the medium speed range and the high speed range respectively,and the feasibility of the measurement system is proved by comparing with the third-party equipment.The comparative experiments show that the speed measuring range of the system can reach 10-1200m/s,the measuring accuracy of low-speed section is less than 0.1m/s,and that of middle-high speed section is less than 0.2%,and the number of effective speed points obtained in the three measuring ranges is not less than 10.This study provides a new method for the integrated and portable design of microwave Doppler velocimetry system in shooting range environment.