Forward-looking Super-resolution Imaging Method Of Radar For Ground Or Sea-surface Target

Forward-looking high-resolution imaging of radar refers to the two-dimensional high-resolution imaging on the target region directly in front of the airborne radar platform,which is also an important function urgently needed by the radar and can greatly improve the aircraft's ability to detect,track and strike the target on the ground or sea.However,traditional Synthetic Aperture Radar(SAR)and Doppler Beam Sharpening(DBS)technique don't have the high-resolution imaging ability in the forward-looking area.Therefore,it is urgent to explore ways to realize the high-resolution imaging in the forward-looking area of radar platform.In view of the difficulty that the existing monostatic radar imaging system cannot realize the forward-looking high-resolution imaging,this thesis,centering on the real aperture scanning radar imaging system,carries out the research on the forward-looking super-resolution imaging approach of radar to the ground or sea surface,which laying a theoretical foundation for the systematic research and application of the radar forward-looking imaging.The main contents are as follows:1.In the forward-looking imaging system of scanning radar,According to the geometrical relationship between the radar platform and the imaging scene,the radar forward-looking imaging geometric model is established.Besides,the echo distance history is derived and the echo rule is analyzed.Finally,the azimuthal convolution model of echo is established to provide theoretic support for the realization of radar forward-looking azimuthal super-resolution by the deconvolution approach.2.For the low-resolution problem of scanning radar imaging in azimuth direction,based on the Gaussian and Poisson hypothesis respectively,this thesis presents two forward-looking super-resolution imaging approaches of scanning radar for ground targets,which can effectively restrain the noise amplification effect of the convolution inversion process,and significantly increase the forward-looking azimuthal resolution of scanning radar imaging under the noise background.3.According to the statistical distribution characteristic of sea clutter,this thesis puts forward two front super-resolution imaging approaches of scanning radar for sea-surface targets based on the Rayleigh assumption.The approaches are able to restrain the received clutter interference,avoid false targets,and significantly promote the azimuthal resolution and imaging quality in forward-looking scanning radar.The model and super-resolution imaging algorithms mentioned above have been verified by simulation experiment or measured data.The proposed approach can realize the forward-looking high-resolution imaging function of scanning radar for ground and sea-surface target,which is used to solve the low-resolution problem in the forward-looking imaging field of real aperture scanning radar.