The Study Of Clutter Suppression And Target Detection In Terahertz Radio Fuze

Terahertz detection is an emerging detection technique in recent years.The reflected electromagnetic wave from target signal is utilized for detection and imaging of targets.For the excellent Anti-interference capability and high down-range resolution,terahertz detection technology is widely used in military and civil applications.In the applications of terahertz fuze,the desired signals are generally overwhelmed by strong ground clutter,and it has serious impacts on the target detection and imaging.In addition,the target movement also affects the accuracy of the target detection.To resolve the problem above-mentioned,the main content of this thesis is summarized as follow.(1)Terahertz radio fuze is used to detect ground slowly moving targets,due to the randomness and strong directivity of ground intensity distribution scatters,resulting fluctuation violent of ground clutter spectrum.Large translation and stretching of ground clutter spectrum are caused by high-speed movement of platform.This makes it difficult to detect ground slowly moving targets extremely.In this thesis,an adaptive Gaussian frequency domain cancellation algorithm is proposed.By estimating the center and spectral width of the clutter spectrum accurately,a corresponding Gaussian clutter model is established,and then the clutter model is used to cancel the echo signal in the frequency domain.Compared with the existing algorithms,the clutter suppression effect of the proposed algorithm is better in the same measurement mode.(2)The problem of extended target detection is discussed.Due to the relative movement between the fuze and the target,the high-resolution image will be severely distorted,which will seriously affect the detection of the target.To solve this problem,a algorithm for detecting of moving range-spread targets based on waveform contrast is proposed in this thesis.It can complete the speed compensation of the moving target well and has a good detection effect even for low signal to noise ratio.Simulated experiments are carried out to verify the advantages and effectiveness of the proposed algorithm.(3)The design and realization of terahertz fuze scheme is studied.A complete block diagram of terahertz fuze system is given,and the design of a horn antenna suitable for the terahertz band is completed.According to the schematic diagram,a prototype of fuze system is designed.On the basis of this prototype,a field test platform is built,and the feasibility of the system is verified by echo data analysis.