Time-dependent seafloor acoustic backscatter (10–100 kHz)

Sternlicht, Daniel D.; Moustier, Christian P. de

doi:10.1121/1.1608018

Cited by 58 publications

(29 citation statements)

References 34 publications

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“…This explains the remaining relatively strong backscattering of the till even at higher incidence. Similar results showing the most pronounced backscatter decay below 5°are provided by Sternlicht and deMoustier (2003). who modelled the angular response for clay.…”

Section: Loss Of Layer Reverberation By Reflection Losssupporting

confidence: 72%

Effects of using inclined parametric echosounding on sub-bottom acoustic imaging and advances in buried object detection

et al. 2015

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This study reports an adaptation of a parametric echosounder system using 15 kHz as secondary frequency to investigate the angular response of sub-bottom backscatter strength of layered mud, providing a new method for enhanced acoustic detection of buried targets. Adaptions to achieve both vertical (0°) and non-vertical inclination (1-15°, 30°, 45°and 60°) comprise mechanical tilting of the acoustic transducer and electronic beam steering. Data were acquired at 18 m water depth at a study site characterized by a flat, muddy seafloor where a 0.1 m diameter power cable lies 1-2 m below the seafloor. Surveying the cable with vertical incidence revealed that the buried cable can hardly be discriminated against the backscatter strength of the layered mud. However, the backscatter strength of layered mud decreases strongly at >3±0.5°incidence and the layered mud echo pattern vanishes beyond 5°. As a consequence, the backscatter pattern of the buried cable is very pronounced in acoustic images gathered at 15°, 30°, 45°and 60°incidence. The size of the cable echo pattern increases linearly with incidence. These effects are attributed to reflection loss from layered mud at larger incidence and to the scattering of the 0.1 m diameter buried cable. Data analyses support the visual impression of superior detection of the cable with an up to 2.6-fold increase of the signal-to-noise ratio at 40°incidence compared to the vertical incidence case.

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Section: Loss Of Layer Reverberation By Reflection Losssupporting

confidence: 72%

Effects of using inclined parametric echosounding on sub-bottom acoustic imaging and advances in buried object detection

et al. 2015

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“…This is further described in Ref. 16. The received echoes are modeled as being the result of scattering at the rough sediment interface and at inhomogeneities in the sediment volume.…”

Section: Introductionmentioning

confidence: 99%

Model-based sediment classification using single-beam echosounder signals

Snellen

Siemes

Simons

2011

The Journal of the Acoustical Society of America

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Acoustic remote sensing techniques for mapping sediment properties are of interest due to their low costs and high coverage. Model-based approaches directly couple the acoustic signals to sediment properties. Despite the limited coverage of the single-beam echosounder (SBES), it is widely used. Having available model-based SBES classification tools, therefore, is important. Here, two modelbased approaches of different complexity are compared to investigate their practical applicability. The first approach is based on matching the echo envelope. It maximally exploits the information available in the signal but requires complex modeling and optimization. To minimize computational costs, the efficient differential evolution method is used. The second approach reduces the information of the signal to energy only and directly relates this to the reflection coefficient to obtain quantitative information about the sediment parameters. The first approach provides information over a variety of sediment types. In addition to sediment mean grain size, it also provides estimates for the spectral strength and volume scattering parameter. The need to account for all three parameters is demonstrated, justifying computational expenses. In the second approach, the lack of information on these parameters and the limited SBES beamwidth are demonstrated to hamper the conversion of echo energy to reflection coefficient.

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“…For a given depth , (4) gives a rough estimation for the number of beams used in the averaging as (6) Taking the beams into account, they span an angular range of as shown in Fig. 7.…”

Section: ) Classification Methodmentioning

confidence: 99%