Research On Radar Forward-looking Super-resolution Imaging Method Based On MIMO Array And Compressed Sensing

Radar forward-looking imaging technology has very broad application requirements in military and civilian fields such as military detection,missile guidance,enemy situation detection,and autonomous driving.Although radar forward-looking imaging technology has been studied for many years,the azimuth resolution of traditional imaging methods based on matched filter technology still depends on the antenna aperture size.In applications where the antenna size is limited,high resolution cannot be achieved.Although the phased array forward-looking correlation imaging method can break through the resolution limitation,it cannot be widely used because of the high manufacturing cost of the phased array antenna.For the problem of low-cost radar forward-looking imaging,after inductively deducing the mathematical model of radar imaging,this paper selects the compressed sensing method as the theoretical basis of super-resolution imaging.Based on the MIMO array radar that can be manufactured at low cost,combined with the compressed sensing theory,the radar forward looking super-resolution imaging method based on MIMO array and compressed sensing is studied.The real reason that the real aperture forward-looking imaging method cannot break through the resolution limitation is that its resolution depends on the antenna aperture size.The aperture extrapolation method can expand the short aperture data.Combined with the compressed sensing sparse reconstruction method,super-resolution imaging could be achieved.On the basis of the MIMO array radar forward-looking imaging signal model,the equivalent phase center processing of the MIMO array element and the real aperture imaging of the array radar based on 2-dimensional beamforming are carried out.On the basis of real aperture imaging of array radar based on 2D beamforming,combined with aperture extrapolation method and CS theory,a super-resolution radar forward-looking imaging method based on sparse aperture extrapolation is realized.In addition,this paper proposes a method for generating a space-time two-dimensional random radiation field based on a MIMO array,which improves the orthogonality of the compressed sensing sampling matrix and makes the radar echo sparse information is more fully utilized.In order to theoretically clarify the principle of radar forward-looking superresolution imaging method based on MIMO array and compressed sensing sampling frame,firstly,a MIMO radar forward-looking imaging signal model based on compressed sensing sampling frame is established,and the principle of radar forward looking super-resolution imaging method of compressed sensing sampling frame is explained.The simulation results show that the effectiveness of the method is proved.