Active Nonlinear Acoustic Sensing of an Object with Sum or Difference Frequency Fields
A number of nonlinear acoustic sensing methods exist or are being developed for diverse areas ranging from oceanic sensing of ecosystems, gas bubbles, and submerged objects to medical sensing of the human body. Our approach is to use primary frequency incident waves to generate second order nonlinea...
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| Format: | Article |
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MDPI AG
2018
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| Online Access: | http://hdl.handle.net/1721.1/115418 https://orcid.org/0000-0001-5895-1157 https://orcid.org/0000-0003-2238-364X https://orcid.org/0000-0003-4369-296X |
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| author | Zhang, Wenjun Liu, Yuming Ratilal, Purnima Cho, Byunggu Makris, Nicholas |
| author2 | Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science |
| author_facet | Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Zhang, Wenjun Liu, Yuming Ratilal, Purnima Cho, Byunggu Makris, Nicholas |
| author_sort | Zhang, Wenjun |
| collection | MIT |
| description | A number of nonlinear acoustic sensing methods exist or are being developed for diverse areas ranging from oceanic sensing of ecosystems, gas bubbles, and submerged objects to medical sensing of the human body. Our approach is to use primary frequency incident waves to generate second order nonlinear sum or difference frequency fields that carry information about an object to be sensed. Here we show that in general nonlinear sensing of an object, many complicated and potentially unexpected mechanisms can lead to sum or difference frequency fields. Some may contain desired information about the object, others may not, even when the intention is simply to probe an object by linear scattering of sum and difference frequency incident waves generated by a parametric array. Practical examples illustrating this in ocean, medical, air and solid earth sensing are given. To demonstrate this, a general and complete second-order theory of nonlinear acoustics in the presence of an object is derived and shown to be consistent with experimental measurements. The total second-order field occurs at sum or difference frequencies of the primary fields and naturally breaks into (A) nonlinear waves generated by wave-wave interactions, and (B) second order waves from scattering of incident wave-wave fields, boundary advection, and wave-force-induced centroidal motion. Wave-wave interactions are analytically shown to always dominate the total second-order field at sufficiently large range and carry only primary frequency response information about the object. As range decreases, the dominant mechanism is shown to vary with object size, object composition, and frequencies making it possible for sum or difference frequency response information about the object to be measured from second-order fields in many practical scenarios. It is also shown by analytic proof that there is no scattering of sound by sound outside the region of compact support intersection of finite-duration plane waves at sum or difference frequencies, to second-order. Analytic expres sions for second-order fields due to combinations of planar and far-field wave-wave interactions are also derived as are conditions for when wave-wave interactions will dominate the second order field. Keywords: nonlinear acoustics; parametric array; sum and difference frequency sensing; nonlinear scattering |
| first_indexed | 2024-09-23T10:03:52Z |
| format | Article |
| id | mit-1721.1/115418 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T10:03:52Z |
| publishDate | 2018 |
| publisher | MDPI AG |
| record_format | dspace |
| spelling | mit-1721.1/1154182022-09-30T18:41:30Z Active Nonlinear Acoustic Sensing of an Object with Sum or Difference Frequency Fields Zhang, Wenjun Liu, Yuming Ratilal, Purnima Cho, Byunggu Makris, Nicholas Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology. Department of Mechanical Engineering Zhang, Wenjun Liu, Yuming Ratilal, Purnima Cho, Byunggu Makris, Nicholas A number of nonlinear acoustic sensing methods exist or are being developed for diverse areas ranging from oceanic sensing of ecosystems, gas bubbles, and submerged objects to medical sensing of the human body. Our approach is to use primary frequency incident waves to generate second order nonlinear sum or difference frequency fields that carry information about an object to be sensed. Here we show that in general nonlinear sensing of an object, many complicated and potentially unexpected mechanisms can lead to sum or difference frequency fields. Some may contain desired information about the object, others may not, even when the intention is simply to probe an object by linear scattering of sum and difference frequency incident waves generated by a parametric array. Practical examples illustrating this in ocean, medical, air and solid earth sensing are given. To demonstrate this, a general and complete second-order theory of nonlinear acoustics in the presence of an object is derived and shown to be consistent with experimental measurements. The total second-order field occurs at sum or difference frequencies of the primary fields and naturally breaks into (A) nonlinear waves generated by wave-wave interactions, and (B) second order waves from scattering of incident wave-wave fields, boundary advection, and wave-force-induced centroidal motion. Wave-wave interactions are analytically shown to always dominate the total second-order field at sufficiently large range and carry only primary frequency response information about the object. As range decreases, the dominant mechanism is shown to vary with object size, object composition, and frequencies making it possible for sum or difference frequency response information about the object to be measured from second-order fields in many practical scenarios. It is also shown by analytic proof that there is no scattering of sound by sound outside the region of compact support intersection of finite-duration plane waves at sum or difference frequencies, to second-order. Analytic expres sions for second-order fields due to combinations of planar and far-field wave-wave interactions are also derived as are conditions for when wave-wave interactions will dominate the second order field. Keywords: nonlinear acoustics; parametric array; sum and difference frequency sensing; nonlinear scattering 2018-05-16T20:05:41Z 2018-05-16T20:05:41Z 2017-09 2017-07 2018-05-04T18:22:54Z Article http://purl.org/eprint/type/JournalArticle 2072-4292 http://hdl.handle.net/1721.1/115418 Zhang, Wenjun et al. “Active Nonlinear Acoustic Sensing of an Object with Sum or Difference Frequency Fields.” Remote Sensing 9, 9 (September 2017): 954 © 2017 The Authors https://orcid.org/0000-0001-5895-1157 https://orcid.org/0000-0003-2238-364X https://orcid.org/0000-0003-4369-296X http://dx.doi.org/10.3390/RS9090954 Remote Sensing Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/ application/pdf MDPI AG MDPI |
| spellingShingle | Zhang, Wenjun Liu, Yuming Ratilal, Purnima Cho, Byunggu Makris, Nicholas Active Nonlinear Acoustic Sensing of an Object with Sum or Difference Frequency Fields |
| title | Active Nonlinear Acoustic Sensing of an Object with Sum or Difference Frequency Fields |
| title_full | Active Nonlinear Acoustic Sensing of an Object with Sum or Difference Frequency Fields |
| title_fullStr | Active Nonlinear Acoustic Sensing of an Object with Sum or Difference Frequency Fields |
| title_full_unstemmed | Active Nonlinear Acoustic Sensing of an Object with Sum or Difference Frequency Fields |
| title_short | Active Nonlinear Acoustic Sensing of an Object with Sum or Difference Frequency Fields |
| title_sort | active nonlinear acoustic sensing of an object with sum or difference frequency fields |
| url | http://hdl.handle.net/1721.1/115418 https://orcid.org/0000-0001-5895-1157 https://orcid.org/0000-0003-2238-364X https://orcid.org/0000-0003-4369-296X |
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