نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشگاه تحصیلات تکمیلی کرمان
2 دانشگاه تحصیلات تکمیلی صنعتی و فناوری پیشرفته
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Imaging the depths of the sea faces various challenges because as the water depth increases, the light intensity decreases. Therefore, it is not possible to create a high-resolution image using optical imaging devices. To form a well-resolved image in range and bearing, artificial aperture sonars are used. One of the challenges of using artificial aperture sonars is the presence of motion-induced oscillations due to water currents. These oscillations cause blurring in the formed image as imaging algorithms assume straight motion. The induced oscillations need to be detected and corrected. One method to detect motion errors is using a linear array of phase centers and creating overlap between one or more phase centers at the distance of two consecutive pings. By processing the received signal, overlapped phase centers can detect and correct motion errors. This article presents a simulation and improvement of an algorithm based on overlapped phase centers for an artificial aperture sonar system. In the proposed algorithm, motion errors are first estimated using mutual correlation calculation between the received signals of overlapped phase centers and compensated by phase multiplication. In the basic algorithm, due to the use of different approximations, motion errors are not fully compensated, so by estimating the maximum likelihood of the remaining phase error and compensating it, the algorithm improves the target image point using an enhanced Doppler beamformer algorithm. Simulations demonstrate the satisfactory performance of the proposed algorithm in estimating and correcting motion errors on the platform.
کلیدواژهها [English]
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