Translational motion compensation of ballistic target based on radon transform
Ballistic target translational motion compensation is beneficial to motion parameter extraction. Aiming at the problem of multiple scattering points translational motion compensation, an algorithm is proposed to extract the translational motion parameters of ballistic targets based on using the projection transform of the whole micro-frequency curve by Radon transform in this paper. First, establishing and analyzing the typical ballistic target model and the expressions of scattering points' micro-frequency are solved. Second, target signal is pre-compensated based on radar information and time-frequency transform. And Radon transform is applied to the parameter projection of time-frequency curve. Then translational motion parameters are estimated based on minimum entropy criteria and gauss fitting. Finally, translational motion is compensated by making use of the estimated motion parameters. Simulation results verify the validity of the proposed algorithm.
Overview of Progress in Midcourse Radar Target Recognition
The environment and characteristic of radar target recognition in midcourse is analyzed and the methods of radar target recognition in midcourse are summarized.According to difference of used feature,those methods are divided three categories,namely,methods based on configuration feature,macrodynamics feature and microdynamic feature.The physics foundation and research progress of three methods are expounded and their characteristics are discussed respectively.Finally,the future tendencies of radar target recognition development in midcourse are foretelled.
Experimental study on ground vibration of blasting the boulder with tandem shaped charging warhead
Hazardous effects of blasting the boulder with the new breaking-blasting equipment-tandem shaped charging warhead are mainly air shock wave, seismic wave and blast slung shot. Blast-induced ground vibration is one of the inevitable effects and may cause substantial damage to nearby structures. Started from the formation process and mechanism of ground vibration to study the seismic wave, the research attained curve of vibration velocity of monitoring points by TC-4850 and carried out differential and fast Fourier transform analysis of the curve. And the results concluded that blasting vibration with tandem shaped charging warhead mainly comes from prime charge; the attenuation law can be predicted by Sadev’s Formula. Explosion vibration frequency range is 20-150 Hz, while with the increase of distance from the blasting center, blasting vibration intensity attenuates rapidly, vibration duration increases and vibration frequency gradually reduces. Compared with general rock blasting, its attenuation rate of blasting vibration is faster with higher frequency and smaller impact on buildings, but the harm effects should not be ignored for the special application environment.