Range compensation for backscattering measurements in the difference-frequency nearfield of a parametric sonar

Foote, Kenneth G.

doi:10.1121/1.3688505

Cited by 13 publications

(11 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In each case, the range between the transducers and the cuttlebone was approximately 1.2 m. The far-field ranges for the 70 and 120 kHz transducers (diameter d =13.5 and 12.9 cm) were~0.47 and~0.68 m (Lee 2006;Foote 2012), respectively. During the calibrations and the TS measurements, the 70 and 120 kHz echosounders transmitted 300 and 60 W pulses with durations of 256 μs and 300 μs every 0.2 s, and received the echoes using 6.2 and 12 kHz receiver bandwidths, respectively.…”

Section: Echosounders and Calibrationsmentioning

confidence: 94%

The influence of cuttlebone on the target strength of live golden cuttlefish (Sepia esculenta) at 70 and 120 kHz

Lee

2016

Fish Aquatic Sci

View full text Add to dashboard Cite

To quantitatively estimate the influence of cuttlebone on the target strength (TS) of golden cuttlefish, the cuttlebone was carefully extracted from 19 live cuttlefish caught using traps in the inshore waters around Geojedo, Korea, in early May 2010 and the TS was measured using split-beam echosounders (Simrad ES60 and EY500). The TS-length relationships for the cuttlefish (before the extraction of cuttlebone, Fish Aquat Sci. 17:361-7, 2014) and the corresponding cuttlebone were compared. The cuttlebone length (L b ) ranged from 151 to 195 mm (mean L b = 168.3 mm) and the mass (W b ) ranged from 29.3 to 53.2 g (mean W b = 38.8 g). The mean TS values at 70 and 120 kHz were −33.60 dB (std = 1.12 dB) and −32.24 dB (std = 1.87 dB), respectively. The mean TS values of cuttlebone were 0.19 dB and 0.04 dB lower than those of cuttlefish at 70 and 120 kHz, respectively. For 70 and 120 kHz combined, the mean TS value of cuttlebone was −32.87 dB, 0.11 dB lower than that of cuttlefish (−32.76 dB). On the other hand, the mean TS value of cuttlebone predicted by the regression (TS b = 24.86 log 10 L b -4.86 log 10 λ -22.58, r 2 = 0.85, N = 38, P < 0.01) was −33.10 dB, 0.04 dB lower than that of cuttlefish predicted by the regression (TS c = 24.62 log 10 L c -4.62 log 10 λ -22.64, r 2 = 0.85, N = 38, P < 0.01). That is, the contribution of cuttlebone to the cuttlefish TS determined by the measured results was slightly greater than that by the predicted results. These results suggest that cuttlebone is responsible for the TS of cuttlefish, and the contribution is estimated to be at least 99 % of the total echo strength.

show abstract

Section: Echosounders and Calibrationsmentioning

confidence: 94%

The influence of cuttlebone on the target strength of live golden cuttlefish (Sepia esculenta) at 70 and 120 kHz

Lee

2016

Fish Aquatic Sci

View full text Add to dashboard Cite

show abstract

“…Following Foote (2012), the far-field range for the largest cuttlefish (L = 23.5 cm) was ~1.42 and ~2.27 m, respectively.…”

Section: Echosounders and Tankmentioning

confidence: 99%

“…http://e-fas.org fish was ~1 m. The far-field ranges (r ff = d 2 ⁄2λ) for the f = 70 and 120 kHz transducers (d =13.5 and 12.9 cm) were ~0.47 and ~0.68 m (Lee, 2006;Foote, 2012), respectively. Following Foote (2012), the far-field range for the largest cuttlefish (L = 23.5 cm) was ~1.42 and ~2.27 m, respectively.…”

Section: Echosounders and Tankmentioning

confidence: 99%

“…Measurements of their mantle length (L) and body mass (W) ranged from 15.6 to 23.5 cm (mean L = 17.8; std = 1.8 cm) and 335 to 1,020 (Love, 1971;Foote, 1985;Goddard and Welsby, 1986;Demer and Martin, 1995;McClatchie et al, 1996;Conti and Demer, 2003;McClatchie et al, 2003;Kang et al, 2005;Simmonds and MacLennan, 2005;Lee, 2006;Foote, 2012), but the literature is devoid of TS measurements and models for cuttlefish. Based on the literature, especially Love's summary of fish TS (Love, 1969;1971), we hypothesize that cuttlefish TS is principally dependent on the incidence angle of the acoustic pulse on the cuttlebone, which, for measurements with a vertical echosounder, would be naturally modulated by cuttlefish behavior, particularly tilt angle (θ), during their vertical migration and feeding.…”

Section: Specimen Collection and Preparationmentioning

confidence: 99%

See 1 more Smart Citation

Target Strength Measurements of Live Golden Cuttlefish Sepia esculenta at 70 and 120 kHz

Lee¹,

Demer²

2014

Fisheries and aquatic sciences

View full text Add to dashboard Cite

Cuttlefish Sepia esculenta are commercially important in Korea. Assessments of their biomass currently depend on fishery-landings data, which may be biased. Towards fishery-independent acoustic surveys of cuttlefish, target strength (TS) measurements at 70 and 120 kHz were made of 23 live cuttlefish, in early May 2010. The fish were caught by traps in the inshore waters around Geojedo, Korea. The TS were measured using split-beam echosounders (Simrad ES60 and EY500, respectively). The cuttlefish mantle lengths (L) ranged from 15.6 to 23.5 cm (mean L=17.8 cm) and their masses (W) ranged from 335 to 1020 g (mean W=556.1 g). Their mean TS values at 70 and 120 kHz were -33.01 dB (std=1.39 dB) and -31.76 dB (std=2.15 dB), respectively. The mean TS at 70 kHz was 0.17 dB higher than the TS-length relationship resulting from a least-squares fit to the data (TS = 24.67 log 10 L (cm) -64.03, r 2 = 0.52, N=23). The mean TS at 120 kHz was 0.45 dB higher than the fitted TS-length relationship (TS = 40.59 log 10 L (cm) -82.96, r 2 = 0.58, N=23). The differences between the mean TS values and an equation regressed from all of the TS measurements at both frequencies (TS = 24.92 log 10 L (m) -4.92 log 10 λ (m) -22.82, r 2 = 0.86, N=46) was 0.22 dB at 70 kHz and 0.31 dB at 120 kHz, respectively.

show abstract

“…Admittedly, the array was virtual, existing in space away from the transducer, as the formation of an exceptionally directional beam at very low frequencies depends on the cumulative effect of the nonlinearity inherent in the medium on the propagating and interacting primary, high-frequency waves. 34 A scheme for quantification of parametric sonar echoes has been developed, 35,36 drawing on a computational model for the difference-frequency nearfield of the parametric sonar, i.e., the nearfield. 37,38 In some underwater geophysical investigations, measurements are inevitably made in the nearfield, for example, with high-frequency sidescan sonars operating at short ranges.…”

Section: B Importance Of the Nearfieldmentioning

confidence: 99%

Discriminating between the nearfield and the farfield of acoustic transducers

Foote

2014

The Journal of the Acoustical Society of America

Self Cite

View full text Add to dashboard Cite

Measurements of the performance of acoustic transducers, as well as ordinary measurements made with the same, may require discriminating between the farfield, where the field is spherically divergent, and the complementary nearfield, where the field structure is more complicated. The problem is addressed for a planar circular piston projector, with uniform normal velocity distribution, mounted in an infinite planar rigid baffle. The inward-extrapolated farfield pressure amplitude p f is compared with the exact nearfield pressure amplitude p n , modeled by the Rayleigh integral, through the error 20 log jp f /p n j. Three sets of computations are performed for a piston with wavenumber-radius product ka ¼ 10: normalized pressure amplitudes and error versus range at angles corresponding to beam pattern losses of 0, 10, 20, and 30 dB; error versus angle at three ranges, a 2 /k, pa 2 /k, and 10a 2 /k, where k is the wavelength; and range versus angle for each of two inward-bounded errors, 1 and 0.3 dB. By reciprocity, the results apply equally to the case of a baffled circular piston receiver with uniform sensitivity over the active surface. It is proposed that proximity criteria for measurements of fields associated with circular pistons be established by like modeling, and that a quality factor be assigned to measurements on the basis of computed errors.

show abstract

Range compensation for backscattering measurements in the difference-frequency nearfield of a parametric sonar

Cited by 13 publications

References 34 publications

The influence of cuttlebone on the target strength of live golden cuttlefish (Sepia esculenta) at 70 and 120 kHz

The influence of cuttlebone on the target strength of live golden cuttlefish (Sepia esculenta) at 70 and 120 kHz

Target Strength Measurements of Live Golden Cuttlefish Sepia esculenta at 70 and 120 kHz

Discriminating between the nearfield and the farfield of acoustic transducers

Contact Info

Product

Resources

About