Circular Sar Three-dimensional Imaging Technology Research

Synthetic Aperture Radar (SAR) is a kind of microwave imaging radar system which can operation under the all-time and all-weather condition. Because of the limit of the traditional linear SAR’s observation angle, the information that we can obtain is limited and we can’t obtain the scene’s three-dimensional imaging. Circular SAR (CSAR) breaks up this restriction with the special circular motion path, and then we can realize the objectives of improving the resolution and obtaining the true three-dimensional imaging capability. This predominance makes circular SAR have wide application foreground in many areas, such as high-resolution imaging, military reconnaissance, disaster monitoring and environment protection, and be becoming one of the focuses in the radar imaging field.This dissertation focuses on the system theories and imaging methods of the circular SAR. The main contributions are presented as follows:(1) We build the echo signal model of the circular SAR system, and analyze the mechanism of its three-dimensional imaging capability. Using mathematical method, we deduce the three-dimensional resolution formula under the condition of ideal point target in focusing plane with full aspect angle (360°) observation. These establish the foundation for CSAR three-dimensional imaging.(2) Under the conditional of far field, through the reasonable approximate, we deduce the mathematical model of circular SAR imaging and present a new parameterized circular SAR three-dimensional imaging method based on the Hough transform. Then we analyze the performances of the presented method by simulation.(3) According to the circular SAR’s system model and echo signal model, we study and realize the circular SAR three-dimensional imaging algorithm based on wavenumber domain, and then analyze the performances. Finally, the feasibility of this method is assessed using simulated data.(4) Using the three-dimensional imaging method based on wavenumber domain, we deal with and analyze the experimental data sets and obtain the real scene’s three-dimensional imaging. This dissertation carries out research on circular SAR with focuses on three-dimensional imaging algorithms, confirms the validity of the proposed methods by simulated and measured data, and enriches the theories about the circular SAR three-dimensional imaging. With the development of the circular SAR technology, it will be applied in various fields.