Imaging Radar Altimeter Imaging Simulation And Experimental Data Processing

Zhang Xiangkun(Aircraft Design)Directed by:Liu Heguang, Zhang YunhuaThis thesis is supported by the National 863 project"Key Technology of Spaceborne Three-Dimensional Imaging Altimeter". The main work of this thesis is to realize the 2D imaging processing of the experimental raw data, which lays a solid foundation for 3D imaging. The algorithms are developed firstly based on the simulated raw data, and then applied to practical raw data. All the algorithms are realized based on the MATLAB and IDL software platform and successfully applied to the imaging processing of experimental raw data. In the first and second chapter,Spaceborne Three-Dimensional Imaging Altimeter is introduced briefly. The algorithm of 2D imaging is studied and the mathematic model for imaging is established in the third chapter. During the phase of simulation, the effects resulted from system parameters, window functions, are investigated. In the fourth chapter, two methods for synthetic aperture processing in azimuthal direction are studied and applied to the data of airborne experiment. One is unfocus method and the other is focus method. Different resolution got by both methods are compared and analyzed in this chapter. In the focus method, the methods of multilook and the estimation of Doppler parameters are discussed.Several methods of image post-processing are studied in the fifth chapter. They are gray scale adjustment, Wienner filtering method and pseudo color enhance. With these technologies used, the images are relatively easier to read and the targets in the images are more clearly shown. At last, the main works in this thesis are summarized. At the same time, several future works are outlooked.