Near-field Three-dimensional Imaging Algorithm For Array-based Radar

Near-field array-based radar imaging has unique advantages in penetrability,resolution,target characteristic,etc.Therefore it has a wide application prospect in industry,trafficking and medicine.In this thesis,the near-field three-dimensional imaging algorithm for planner array,cylindrical array and multistatic array are studied respectively.The imaging performance of the array is analyzed and the general method of the array parameter design is summarized.In chapter ?,the relationship between the spectrum and target reflectivity under the condition of near-field planar array is established.After analyzing the imaging performance and the constraints for the design of array parameters,the general methods of array design are summarized and the design example is given.Meanwhile,the imaging principle and imaging steps of time-domain correlation algorithm,backprojection algorithm,range stacking algorithm and range migration algorithm for planar array are analyzed theoretically and compared.In chapter ?,the relationship between the spectrum and target reflectivity under the condition of near-field turntable is established.The constraints of array parameter design and the imaging performance measured on single-frequency and wide-band are discussed.Then the frequency-domain imaging algorithm suitable for single-frequency and wide-band turntable are analyzed and applied for the measured data,respectively.Aiming at the shortcomings of the time-domain algorithm,the dimension-reduced time domain correlation algorithm for cylindrical array imaging is proposed.The proposed method preserves the advantage of time domain correlation method without interpolation and ensures the imaging precision.In chapter ?,the wavenumber spectrum measured on multistatic configuration is analyzed.A novel frequency-domain imaging method is proposed for single-inputmultiple-output array.Its FFT-based subimaging scheme greatly improves the computational efficiency compared with time-domain method,and avoids the frequency-domain interpolation.In addition,a rearrangement-free frequency-domain imaging algorithm for multiple-input-multiple-output array is proposed.Compared with MIMO-RMA,the method preserves the high efficiency of the FFT-based method and can be implemented for transmitting and receiving arrays of different length.