Research On Non-uniform Liner Array Three-dimensional ISAR Imaging

Three-Dimension radar can use the combination of synthetic aperture(Inverse synthetic aperture)and real aperture to achieve 3-D resolution.This dissertation introduces an 3-D imaging method using array ISAR,the traditional 2-D image is the projection of the target,the projective plane is called range-azimuth plane.As for array 3-D ISAR,when the array is perpendicular to the range-azimuth plane,the array antenna obtain the target echo,then the information of scattering point can be obtained by the caculation.3-D imaging has the ability to improve the effect of target tracking and object identification.Considering the distribution of array element may be heterogeneous,the target is sparsity,this dissertation also research another algorithm to achieve the 3-D imaging.Specific research contents are as follows.This dissertation introduces the pricinple of ISAR,studies and analyses the basic manner of working,using the array under the rotation-model to work.The spatial resolution is analysed,the resolution ratio in the array dimension is related to the wave length,the target height,the array length,the higher resolution ratio as the longer array.Projection-slice theory proves the feasibility of this 3-D imaging.This dissertation analyses an algorithm to verificate this method of 3-D imaging,compare the different results using different number of array elements.The polarimetric model is studied,in the following simulation,the array element is transceiver common element.in terms of equivalent phase center,all varieties of array can be equivalent to transceiver array.According to the nyquist theorem,the false imaging may appear if the array elements spacing is long.So,two kinds of nonuniform linear array are proposed to avoid grating lobe.Base on the research about the basic manner of working and the 3-D imaging methodA,this dissetation analyses the IAA algorithm to achieve 3-D imaging using this nonuniform linear array,compares the different results.Base on the rasearch about nonuniform linear array,this dissertation introduces the Compressed Sensing,analyses the feasibility of 3-D imaging using this method,.several algorithms are proposed,simulation experiment is carried out.This dissertation also compares different results of different algorithms.