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Application of sar techniques in an ultrasound testbed

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2008
Solak, Güven
In this thesis, an ultrasound testbed is designed in order to practice the Synthetic Aperture Radar (SAR) techniques. The thesis work is built on the fundamentals of SAR theory. In this respect, four different methods for the reconstruction of SAR image are considered. The ultrasonic testbed is composed of a mobile vehicle where the ultrasound transmitter and receiver are mounted. An analog circuit is designed in order to condition the transmitted and received signals. The receiving signal is processed in a personal computer using MATLAB routines. A GUI is designed for user friendly operation. Different experiments are done with the designed system. The theoretical and practical results for SAR imaging are compared. It is shown that the designed system functions properly with a good approximation to the theoretical results. The deviations from the theoretical results are caused by the idealistic assumptions as well as the distortions introduced by the practical system. More specifically, some of the distortions are generated by the nonuniform velocity of the moving platform, the phase distortion due to the analog filters and imperfect filtering during down-conversion. While the sources of distortions certainly affect the SAR system response, the implemented system is valuable for the practical analysis of SAR system performance.