Near Artillery Shells Instantaneous Speed Extraction Problem In The Bore

The background of this paper is the measurement of the instantaneous velocity of close-quarters cannon. This paper consists of two parts. The first part mainly discusses the theories, and we do the research base on the traditional and the modern time-frequency analysis methods. On the one hand with the traditional method, the instantaneous velocity of the in-bore projectile is measured by the algorism of STFT and WVD, and their merits and deficits are analyzed respectively. By the end of this part, one novel algorism is proposed to integrate the merits of STFT and WVD, and it is applied at the end of this paper. On the other hand with the modern method, the in-bore projectile's instantaneous velocity is measured base on the DPT algorism, the measuring accuracy can be very well, however, our research shows that this algorism has some deficits that limit its practical application.The second part of this paper mainly discusses the radar echo data acquisition and processing. One simple and low-cost system which based on the soundcard and MATLAB is designed to measure the in-bore projectile's instantaneous velocity, due to the low sample rate of the soundcard, a new method is proposed to get the correct velocity under sub-sampling condition. At last, under multi-barrel condition, the methods are researched to distinguish different projectile and get their velocity. A freewill signal generator is designed base on the soundcard and MATLAB to simulate the radar echo from several projectiles. And we use the DAQ card to acquire the data which send by the generator and a GUI is designed to show the processing result.