Research On Downward-looking High-resolution Imaging Method Of Stochastic Radiation Radar

Stochastic radiation radar downward-looking high-resolution imaging method is of great value in many applications,such as the UAV hovering site selection and radar downward-looking ground mapping.However,there are still many problems that need to be solved urgently in this technology,such as the imaging mechanism of stochastic radiation radar,the design of the stochastic radiation field,and the high-resolution reconstruction method.This thesis focuses on the research on the stochastic radiation radar downward-looking high-resolution imaging method,Aiming at the key issues such as the imaging mechanism of stochastic radiation radar,the design of the stochastic radiation field,and the high-resolution imaging method,focuses on the three methods which are mirror target suppression method based on adaptive step frequency accumulation,low redundancy radiation field construction method based on interpulse frequency hopping accumulation,and high-resolution imaging method based on singular value weighted truncation(SVWT).The main research content is as follows:1.According to the system structure of stochastic radiation radar,the echo model of the stochastic radiation radar is established,which lay the foundation for the subsequent research on downward-looking high-resolution imaging methods.2.The mechanism of downward-looking high-resolution imaging of stochastic radiation radar is researched,the constraints between the field of view of stochastic radiation radar imaging and radar system parameters are analyzed,and an adaptive step frequency accumulation method is proposed to achieve mirror target suppression.3.The quantitative representation relationship between the stochastic radiation field and the radar system parameters is derived,the influence of the amplitude,phase,and frequency hopping mode of the transmitted signal on the imaging performance of the stochastic radiation field is analyzed,and a low redundancy stochastic radiation field construction method is studied.From the perspective of system information acquisition,it ensures stochastic radiation radar downward-looking high-resolution imaging.4.The impact of system noise on imaging performance is analyzed,the high-resolution reconstruction problem of stochastic radiation radar is transformed into a constrained optimization problem,and a high-resolution imaging method based on singular value weighted truncation(SVWT)is studied.From the perspective of data processing,it achieves stochastic radiation radar downward-looking high-resolution imaging in a low SNR environment.The effectives of the above methods and models are demonstrated by the simulations.Through the above three methods,downward-looking high-resolution imaging can be achieved under the low SNR and large field of view circumstances.