TY - JOUR
T1 - Spatiotemporal Deconvolution of Hydrophone Response for Linear and Nonlinear Beams - Part II
T2 - Experimental Validation
AU - Wear, Keith A.
AU - Shah, Anant
AU - Baker, Christian
N1 - Publisher Copyright:
© 1986-2012 IEEE.
PY - 2022/4/1
Y1 - 2022/4/1
N2 - This article reports experimental validation for spatiotemporal deconvolution methods and simple empirical formulas to correct pressure and beamwidth measurements for spatial averaging across a hydrophone sensitive element. The method was validated using linear and nonlinear beams transmitted by seven single-element spherically focusing transducers (2-10 MHz; ${F}$ /#: 1-3) and measured with five hydrophones (sensitive element diameters ${d}_{g}$ : 85-1000 $\mu \text{m}$ ), resulting in 35 transducer/hydrophone combinations. Exponential functions, exp( $-\alpha {x}$ ), where ${x} = {d}_{g}$ /( $\lambda _{{1}}{F}$ /#) and $\lambda _{{1}}$ is the fundamental wavelength, were used to model focal pressure ratios ${p}'/{p}$ (where ${p}'$ is the measured value subjected to spatial averaging and ${p}$ is the true axial value that would be obtained with a hypothetical point hydrophone). Spatiotemporal deconvolution reduced $\alpha $ (followed by root mean squared difference between data and fit) from 0.29-0.30 (7%) to 0.01 (8%) (linear signals) and from 0.29-0.40 (8%) to 0.04 (14%) (nonlinear signals), indicating successful spatial averaging correction. Linear functions, Cx + 1, were used to model FWHM'/FWHM, where FWHM is full-width half-maximum. Spatiotemporal deconvolution reduced ${C}$ from 9% (4%) to -0.6% (1%) (linear signals) and from 30% (10%) to 6% (5%) (nonlinear signals), indicating successful spatial averaging correction. Spatiotemporal deconvolution resulted in significant improvement in accuracy even when the hydrophone geometrical sensitive element diameter exceeded the beam FWHM. Responsible reporting of hydrophone-based pressure measurements should always acknowledge spatial averaging considerations.
AB - This article reports experimental validation for spatiotemporal deconvolution methods and simple empirical formulas to correct pressure and beamwidth measurements for spatial averaging across a hydrophone sensitive element. The method was validated using linear and nonlinear beams transmitted by seven single-element spherically focusing transducers (2-10 MHz; ${F}$ /#: 1-3) and measured with five hydrophones (sensitive element diameters ${d}_{g}$ : 85-1000 $\mu \text{m}$ ), resulting in 35 transducer/hydrophone combinations. Exponential functions, exp( $-\alpha {x}$ ), where ${x} = {d}_{g}$ /( $\lambda _{{1}}{F}$ /#) and $\lambda _{{1}}$ is the fundamental wavelength, were used to model focal pressure ratios ${p}'/{p}$ (where ${p}'$ is the measured value subjected to spatial averaging and ${p}$ is the true axial value that would be obtained with a hypothetical point hydrophone). Spatiotemporal deconvolution reduced $\alpha $ (followed by root mean squared difference between data and fit) from 0.29-0.30 (7%) to 0.01 (8%) (linear signals) and from 0.29-0.40 (8%) to 0.04 (14%) (nonlinear signals), indicating successful spatial averaging correction. Linear functions, Cx + 1, were used to model FWHM'/FWHM, where FWHM is full-width half-maximum. Spatiotemporal deconvolution reduced ${C}$ from 9% (4%) to -0.6% (1%) (linear signals) and from 30% (10%) to 6% (5%) (nonlinear signals), indicating successful spatial averaging correction. Spatiotemporal deconvolution resulted in significant improvement in accuracy even when the hydrophone geometrical sensitive element diameter exceeded the beam FWHM. Responsible reporting of hydrophone-based pressure measurements should always acknowledge spatial averaging considerations.
KW - Beamwidth measurement
KW - deconvolution
KW - hydrophone
KW - membrane
KW - pressure measurement
KW - spatial averaging
UR - http://www.scopus.com/inward/record.url?scp=85124772047&partnerID=8YFLogxK
U2 - 10.1109/TUFFC.2022.3150179
DO - 10.1109/TUFFC.2022.3150179
M3 - Article
C2 - 35143394
AN - SCOPUS:85124772047
SN - 0885-3010
VL - 69
SP - 1257
EP - 1267
JO - IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
JF - IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
IS - 4
ER -