The New Arrays, Three-dimensional Sar Key Technologies Study

The linear array synthetic aperture radar (LASAR) is a new three dimensional (3D) SAR system, which uses a linear array antenna mounted in traverse direction to synthesize a 2D virtural antenna array with the motion of the platform to achieve the along track and the cross track resolution; combing with the pulse compression technique in the range direction, the 3D resolutions are obtained. This dissertation mainly researches the theories of the 3D SAR imaging, the 3D imaging method, the optimization of the antenna array and the analysis of the motion measurement errors. The main contributions of this dissertation are as follows:1. The 3D imaging theories of the linear array SAR are introduced. The"full-active"3D linear array SAR model is build and a new bistatic-based"one-active"3D linear array SAR model are presented. The echo model is build and its 3D spatial ambiguity function (AF) is analyzed repectively. Then the 3D spatial resolutions of them are derived.2. The synthetic methods of the virtual array are studied. The mainlobe and sidelobe characteristic of the 3D AF are issued under the periodic antenna phase center trajectory (APCT) and the pseudo random APCT. The optimal pseudo random APCF distribution is achieved based on the least square error criteria.3. Three 3D imaging methods are mainly researched to focus the 3D linear array SAR data, which are the 3D back projection (BP) method, the 3D range Doppler (RD) method and the presented adaptive sliding-window predicton method based on BP (ASP-BP). The main steps of these methods are presented and the computational costs and 3D image's focusing quality of them are analyzed and compared respectively. The simulation results validated the feasibility of these 3D imaging methods.4. The motion measurement errors (MMEs) are analyzed for the 3D linear array SAR. The MMEs models are build and the system's maximum allowable MMEs are derived. Combining the numerical simulation results, the influences of the MMEs to the 3D image focusing are analyzed.5. To validate the feasibility of the"one-active"linear array SAR system, the ground experiments are peformed. The point scatterers'3D SAR image is obtained using the 3D BP method. Contrast to the real 3D scene, the experimental results matched it soundly, which validated the feasibility of the"one-active"linear array SAR system again.