A miniature high resolution 3-D imaging sonar

Josserand, Timothy M.; Wolley, Jason

doi:10.1016/j.ultras.2010.09.003

Cited by 8 publications

(2 citation statements)

References 4 publications

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“…Ultrasonic time-of-flight (ToF) measurements are a common technique in many research and industrial fields, spanning from ranging applications [ 1 , 2 , 3 , 4 ] to human-computer interaction [ 5 , 6 ] to non-destructive testing (NDT) of materials [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. The basic concept of ultrasonic ToF measurements is that a signal is transmitted from an ultrasonic transducer and received at a later time by the same or a different transducer.…”

Section: Introductionmentioning

confidence: 99%

Development of an Accurate and Robust Air-Coupled Ultrasonic Time-of-Flight Measurement Technique

Bühling

Küttenbaum

Maack

et al. 2022

Sensors

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Ultrasonic time-of-flight (ToF) measurements enable the non-destructive characterization of material parameters as well as the reconstruction of scatterers inside a specimen. The time-consuming and potentially damaging procedure of applying a liquid couplant between specimen and transducer can be avoided by using air-coupled ultrasound. However, to obtain accurate ToF results, the waveform and travel time of the acoustic signal through the air, which are influenced by the ambient conditions, need to be considered. The placement of microphones as signal receivers is restricted to locations where they do not affect the sound field. This study presents a novel method for in-air ranging and ToF determination that is non-invasive and robust to changing ambient conditions or waveform variations. The in-air travel time was determined by utilizing the azimuthal directivity of a laser Doppler vibrometer operated in refracto-vibrometry (RV) mode. The time of entry of the acoustic signal was determined using the autocorrelation of the RV signal. The same signal was further used as a reference for determining the ToF through the specimen in transmission mode via cross-correlation. The derived signal processing procedure was verified in experiments on a polyamide specimen. Here, a ranging accuracy of <0.1 mm and a transmission ToF accuracy of 0.3μs were achieved. Thus, the proposed method enables fast and accurate non-invasive ToF measurements that do not require knowledge about transducer characteristics or ambient conditions.

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Section: Introductionmentioning

confidence: 99%

Development of an Accurate and Robust Air-Coupled Ultrasonic Time-of-Flight Measurement Technique

Bühling

Küttenbaum

Maack

et al. 2022

Sensors

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show abstract

“…T ransferring weak sound efficiently is of particular importance in various acoustic technologies, including sonar systems 1 , speech communications 2 , medical imaging 3 , acoustic surveillance 4 , and many more. In classical acoustic theory, the amplitude diminishes in a free-field environment due to geometric spreading and losses, which critically limit the detection capability of sound transceivers.…”

mentioning

confidence: 99%

Remote whispering metamaterial for non-radiative transceiving of ultra-weak sound

Zhang

Wei

et al. 2021

Nat Commun

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Transceiving ultra-weak sound typically relies on signal pre-amplification at the transmitting end via active electro-acoustic devices, which inherently perturbs the environment in the form of noise that inevitably leads to information leakage. Here we demonstrate a passive remote-whispering metamaterial (RWM) enabling weak airborne sound at audible frequencies to reach unprecedented signal enhancement without altering the detected ambient soundscape, which is based on the extraordinary scattering properties of a metamaterial formed by a pair of self-resonating subwavelength Mie meta-cavities, constituting the acoustic analogy of Förster resonance energy transfer. We demonstrate efficient non-radiative sound transfer over distances hundreds times longer than the radius of the meta-cavities, which enables the RWM to recover weak sound signals completely overwhelmed by strong noise with enhanced signal-to-noise ratio from −3 dB below the detection limit of 0 dB in free space to 17.7 dB.

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Deep sub-wavelength acoustic transmission enhancement and whisper via the monopole resonance in meta-cavities

Lei

Wang

et al. 2023

Applied Acoustics

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A miniature high resolution 3-D imaging sonar

Cited by 8 publications

References 4 publications

Development of an Accurate and Robust Air-Coupled Ultrasonic Time-of-Flight Measurement Technique

Development of an Accurate and Robust Air-Coupled Ultrasonic Time-of-Flight Measurement Technique

Remote whispering metamaterial for non-radiative transceiving of ultra-weak sound

Deep sub-wavelength acoustic transmission enhancement and whisper via the monopole resonance in meta-cavities

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