Radiometric Image Simulation And Imaging Analysis For Synthetic Aperture Interferometric Radiometer

Since nearly half century, the microwave radiometric surveying technology had made a remarkable progress. The newly emerged sensors, such as millimeter camera and interferometric radiometer, even more promoted the development of technology in passive microwave remote sensing. Under such circumstance, this research focuses on the radiometric image simulation and the imaging technique of synthetic aperture interferometric radiometer. The main works and conclusions are as follows.1. The brightness temperature tracing method is proposed for image simulation and a 3-D scene simulation model is present. The essential influencing factors and general requirements are considered such as the rough surface radiation, the sky radiation, the polarization rotation, and the system response. Especially the diffraction of natural radiation by impedance wedge is analyzed, and the antenna temperature calculating formula is achieved by using GTD theory. The model is validated by simulating virtual and real scene, and used to analyze the appeared phenomenology.2. The imaging theory of rotary scanning interferometric radiometer is studied, two more accurate new imaging algorithms based on pseudo-polar FFT and back projection theory are developed. Furthermore the Gridding method and cured surfaces interpolation are analyzed and improved for suiting this case.3. The newly proposed concept of clock scan is further studied and the common rule of the step rotation and continuous rotation are analyzed and summarized. With the given time and temperature resolution the general designing process of clock scan system is present, based on which the potential applications such as GEO, Balloon based sounding and astronomy observation are explored. As an example the application for SPORT project is simulated, the results confirmed its feasibility.4. The near field imaging problem of interferometric radiometer is analyzed, and the limitations and disadvantages of the recently proposed spherical antenna array scheme are point out. Before exploring more feasible imaging method, a limited numerical inverse method is proposed and used for studying the distortions of the conventional imaging method used in near field cases. Furthermore, the sampling formula of near field is deduced, which is identical with the simulation results by numerical method.At last, the research results and conclusions are summarized, the existing problems are pointed out and the future work is also prospected.