Imaging And Point Spread Function Analysis Using Beidou Navigation Satellite Signals

Bistatic synthetic aperture radar imaging using Bei Dou navigation satellite signals is a new remote sensing imaging method.Compared with traditional remote sensing satellites,Bei Dou navigation satellites have a wider coverage and can perform allweather and all-day monitoring,which can provide convenience for ground monitoring in regions with poor climate conditions such as the polar region.Since the navigation satellites are not designed for radar imaging,one of the important problems faced by this imaging result is the imaging resolution.In addition,point spread function play an important role in the design of imaging topology and analysis of imaging resolution.In-depth study of point spread function and its application can further expand the application prospects of this imaging technology.Therefore,this paper studies the area imaging and point spread function based on the Bei Dou navigation satellite signals.The main work and research results are as follows:Firstly,the imaging performance of bistatic radar based on Bei Dou navigation satellite signals is studied.The topology of bistatic imaging is briefly described,and the difference between different satellites,receivers and projection directions as the imaging topology is given.The signal-to-noise ratio of the imaging system is analyzed,then the appropriate integration time and detection distance reference are given.The methods of obtaining the equidistance line and equal doppler line,range resolution,azimuth resolution and resolution unit area of the imaging system based on different topological structures are studied,and their spatial variation characteristics are obtained through simulation experiments.Then the back projection imaging algorithm based on Bei Dou navigation satellite signals was studied.The Bei Dou MEO/IGSO satellites are selected as the signal sources,and the signal processing flow of the imaging algorithm is described in detail in terms of signal synchronization based on direct signal,distance compression based on frequency interpolation,acquisition of precision orbit satellite positions and the principle of back projection.After long time integration accumulation,single-star and multi-star imaging results with good azimuth resolution are obtained.Finally,the point spread function analysis and target separation based on Bei Dou navigation satellite signals imaging are studied.Firstly,the calculation of single-star and multi-star point spread functions are analyzed in detail,and the correctness is verified through comparing the simulation experiment results and the actual imaging results.In order to improve the resolution of the single-star and multi-star imaging results,then the target separation algorithm based on point spread functions is studied,the experimental results verify the feasibility of the algorithm in extracting the scattering center points in the imaging results,and finally reconstructs the frontier contour of the target building in the imaging scene through the target separation algorithm.