Research On ISAR Imaging Algorithm For Spatial Target

After several decades of development,the theory and algorithm of ISAR have been gradually improved,and it has great application value in military and civil use.However,with the increasing importance of space resources in the world,the development of space resources has become a hot spot,and the trend of space warfare is gradually exacerbated.Spatial target has become a hot spot in radar field,and its ISAR imaging research is more and more strategic.In this paper,the micro-Doppler characteristics and ISAR imaging algorithms of space targets are studied.The main contents are as follows:1)The micro-Doppler feature analysis and extraction method of spatial targetFirstly,the point-scattering model of the micro-moving target is established to study the theoretical micro-Doppler characteristics of the three micro-moving targets of spin,precession and nutation.Then,the motion state of the free parts on the space target is studied.The micro-Doppler feature extraction and the micro-Doppler frequency characteristic parameter estimation method are studied.2)ISAR imaging algorithm for space targets with rotating partsISAR imaging for space targets with rotating parts usually produces micro-Doppler phenomena,which reduce the image quality of ISAR and interfere with the resolution of the target.In this paper,we introduce an ISAR imaging algorithm which can effectively remove the micro-Doppler effect.The algorithm can effectively eliminate the micro-Doppler effect by short time Fourier transform(STFT).But there is a problem that the image resolution is not high and the rigid body information is missing.So we propose an improved algorithm based on rigid body parameter estimation,which can obtain better imaging results.3)Interferometric ISAR imaging algorithm based on antenna array for space targetInterferometric inverse synthetic aperture radar(In ISAR)imaging is a high-resolution radar three-dimensional imaging method combining interference technology with ISAR imaging technology.In this paper,we mainly study the interferometric ISAR imaging algorithm based on vertical antenna array.The algorithm uses two vertical antenna arrays to obtain the position information of the space object,which greatly improves the ability of ISAR to distinguish the scattering point of the space target.In this paper,the compensation algorithm of independent scattering point and non-independent scattering point is proposed in the motion compensation method.The proposed ISAR imaging algorithm based on vertical antenna array can effectively solve many problems in the interference ISARimaging technology for complex moving targets.