کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4923867 1430823 2017 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Super-resolution imaging of low-frequency sound sources using a corrected monopole time reversal method
ترجمه فارسی عنوان
تصویربرداری با وضوح فوق العاده از منابع صوتی با فرکانس پایین با استفاده از یک روش معکوس زمان انحصاری تصحیح شده
کلمات کلیدی
معکوس کردن زمان، رزولوشن فضایی، امواج امواج، فیلتر کردن
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی عمران و سازه
چکیده انگلیسی
A limitation of the monopole time reversal (MTR) method, which records and retransmits the monopole field only, is that the spatial resolution of the focus cannot be better than half a wavelength, and therefore it is not suitable for locating low-frequency sound sources. In this paper, the time-reversed pressure field obtained by the MTR method is first transformed into the wavenumber domain, and is then decomposed into a filter term that controls the spatial resolution of the focus and a source term that is related to the sound source and focusing plane. Subsequently, a correction is made to the time-reversed pressure field of the MTR method by replacing its filter with the filter for the time-reversed pressure gradient field of the dipole TR (DTR) method, a constant filter and an empirical filter, which makes it possible to include many more evanescent waves and obtain subwavelength focusing. Numerical simulation and experimental results show that compared to the original MTR method, the corrected one is able to dramatically improve the spatial resolution of the focus at low frequencies. It is also found that the constant filter is applicable when the signal-to-noise ratio (SNR) is high (generally above 30 dB), the filter for the time-reversed pressure gradient field of the DTR method works stably even in the situation of low SNR, and the empirical filter performs best when the SNR is above 10 dB.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Sound and Vibration - Volume 410, 8 December 2017, Pages 303-317
نویسندگان
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