Research On Distributed Radar Imaging Of Moving Target

This thesis presents the research on distributed imaging of non-cooperative moving target. Based on the theory of space spectrum, by considering the contributions and relations of the space expansion of the radar system, the bandwidth of the transmitted signals and the relative motions between the target and the radar stations, we focus on the distributed radar imaging of moving target with bistatic inverse synthetic aperture radar (B-ISAR) as its basic configuration.Firstly, for the special geometry of B-ISAR, a motion decomposition based return signal modeling method is proposed, and the echo obtained by this method can analytically reveal the relations between the geometric distortion, the calibration of the image and the system configuration, the motion of the target. Therefore, the geometric distortion correction and calibration of the image can be seen as a parameter estimation problem. Then the imaging plane of B-ISAR under the condition of general3D moving target is derived, and the geometric distortion and calibration of Range-Doppler (RD) images are analyzed, which are the foundations of the subsequent chapters.Secondly, by exploiting the sparse scattering property of the target under high-frequency radiation, the applications of compressive sensing (CS) in distributed imaging of moving target are studied, which mainly contain two aspects:1) A sparse imaging algorithm with geometric distortion correction and calibration is proposed for B-ISAR.2) For the purpose of high resolution imaging, a sparse fusion imaging method for moving target in T/R-R (transmitter/receiver-receiver) configuration is proposed, which can improve the resolution significantly with very short coherent processing time and at the same time has a relatively low system complexity.Thirdly, a new distributed imaging configuration—distributed multiple input single output ISAR (MISO-ISAR) is presented for high resolution imaging of general target. This imaging system not only has improved resolution but also has enhanced anti-jamming capability, flexibility and viability. As a results, it shows a good compromise between the performance and the practicality.Finally, based on the distributed MISO-ISAR, this thesis proposes a3D imaging method with moving receiver, which can achieve high resolution3D imaging with only a1D transmitter array and a single moving receiver. Therefore, the proposed imaging system is relatively simple and practical.