Design And Implementation Of Miniaturized High Precision Imaging Radar For Sea Surface

Traditional radar for sea imaging is difficult to meet the requirements of small surface unmanned platforms,while MIMO radar,as a new system radar,has the advantages of high resolution and strong real-time performance in the imaging field,and can provide a new observation way for USV.In this paper,we start with the study of MIMO radar imaging,and design a miniaturized high-precision sea imaging radar system based on MIMO radar,the imaging performance of the radar is verified by simulation analysis and imaging experiment.radar miniaturization technology and MIMO imaging radar are combined to design and implement a miniaturized high-precision sea surface imaging radar system,and MIMO radar surface imaging algorithm is studied on this system.First of all,this paper studies the surface scene imaging of MIMO radar,using linear wave theory and two-dimensional wave spectrum model random sea surface,and the Bragg scattering model,double-scale scattering model and shadow modulation function are used to construct the distribution model of the backward scattering coefficient of the sea surface.On this basis,the MIMO radar imaging algorithm is adopted to simulate the random sea surface under different frequency bands and sea conditions,the simulation results show that MIMO radar imaging findings are similar geometric features to the random sea surface.Moreover,the imaging results of the millimeter-wave MIMO radar can retain more sea surface features than the X-band Marine radar.Then,in this paper,the corresponding beamforming for MIMO radar imaging algorithms are studied,analysis the relationship between MIMO radar imaging precision with signal modulation mode and the equivalent aperture antenna array.In view of the imaging algorithm is easy to receive the Interference error of signal spectrum,this paper proposes a frequency estimation algorithm based on ap FFT,weaken the signal waveform distortion during cycle continuation and restraining the interference caused by frequency spectrum leakage component.At the same time,using three frequency estimation device correct the deviation caused by the fence effect,the proposed frequency estimation algorithm apply to beamforming algorithm.The artifact phenomena in MIMO radar imaging results are effectively eliminated,and the imaging accuracy of MIMO radar is improved.Finally,a small high precision surface imaging radar system is designed and implemented.In the hardware platform,the two radar rf front-end modules are connected by cascaded mode,expanding the equivalent antenna array of the sea surface imaging radar,improving the azimuth resolution of the radar,and adding a low-power controller to control the orderly operation of each module in the hardware platform.In terms of software algorithm,the software client of the radar system is designed based on the hardware platform.The normal operation of the sea surface imaging radar system is through the mutual cooperation between various software levels,and the radar system parameters can be adjusted and the radar system imaging results can be displayed by the Host client.The imaging performance of the small high precision sea surface imaging radar system is verified by imaging experiments under different scenes.