Buried object scanning sonar

Schock, Steven G.; Tellier, A.; Wulf, J.; Sara, Jason; Ericksen, M.

doi:10.1109/48.972111

Cited by 57 publications

(42 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This system uses an omnidirectional projector that transmits an FM signal over 3-19 kHz. The wing BOSS is smaller and more mobile than the older generation disk BOSS vehicle [19], as the wing arrays tend to produce less drag than the large circular array. In order to improve the resolution of target imagery, the wing BOSS utilizes time-delay focusing [17] extended to hydrophone data collected over several transmissions.…”

Section: A Boss System and Collected Data Setmentioning

confidence: 99%

Buried Underwater Object Classification Using a Collaborative Multiaspect Classifier

Cartmill

Wachowski

Azimi-Sadjadi

2009

IEEE J. Oceanic Eng.

View full text Add to dashboard Cite

Abstract-In this paper, a new collaborative multiaspect classification system (CMAC) is introduced, which utilizes a group of collaborative decision-making agents capable of producing a highconfidence final decision based on features obtained over multiple aspects. It is also shown how CMAC can be modified to perform multiaspect classification using a decision feedback (DF) strategy. The system is then applied to a buried underwater target classification problem. The results show that CMAC provides excellent multiple-ping classification of mine-like objects while reducing the number of false alarms compared to other multiple-ping classification fusion systems such as nonlinear decision-level fusion (DLF).

show abstract

Section: A Boss System and Collected Data Setmentioning

confidence: 99%

Buried Underwater Object Classification Using a Collaborative Multiaspect Classifier

Cartmill

Wachowski

Azimi-Sadjadi

2009

IEEE J. Oceanic Eng.

View full text Add to dashboard Cite

show abstract

“…Consequently, there has been much recent work to develop high-frequency surface-scanning acoustics, e.g., side-scan sonar, sector-scanning sonar, and swath bathymetry, for object detection on the seabed ͑Simms and Albertson, 2000; Quinn et al, 2002͒. By comparison, there has been limited success in replicating that level of resolution in the subsurface ͑Schock et al, 2001;Bull et al, 2005͒. Chirp or boomer subbottom profilers ͑operating in the range of 0.4 to 24.0 kHz͒ are capable of imaging completely buried structures, but they collapse responses from a 3D environment into 2D vertical slices and therefore provide no cross-dip information. Even after migration, the results are imperfect and confusing sections, commonly degenerated by out-of-plane reflections, especially in areas with rapid structural variations.…”

Section: Introductionmentioning

confidence: 99%

“…Because of that and the poor ground coverage afforded by a sparse mesh of 2D lines ͑with spacing commonly Ն10 m͒, they can do little more than indicate zones with a higher risk. However, when chirp or boomer sources are combined with an array of hydrophones, the reflected waveforms can be recorded in 3D ͑Missiaen, 2005;Scheidhauer et al, 2005͒, and it is possible to image buried objects, as shown within along-track sections by Schock et al ͑2001͒.…”

Section: Introductionmentioning

confidence: 99%

Decimeter-resolution 3D seismic volume in shallow water: A case study in small-object detection

et al. 2008

View full text Add to dashboard Cite

The 3D chirp subbottom profiler provides high-resolution imaging of coastal and inshore seabed and subseabed structure by combining the known, highly repeatable source waveform of chirp profilers with the coherent processing and interpretation afforded by true 3D seismic volumes. Comprising 60 hydrophone groups arranged around a Maltese cross of four chirp transducers, 3D chirp permits acquisition of a true 3D volume with a horizontal resolution of 12.5 cm, providing an excellent base for shallow-water engineering, archaeological, military, and geologic studies. Here, we present results from surveying an atidal basin on the southern coast of England to map bedrock protrusions and the size and distribution of buried objects. The study area of 150ϫ 250 m provided a series of unique challenges, including a large number of discrete objects ranging from tens of centimeters to several meters in size, buried in a thin veneer ͑0.5 to 1.5 m͒ of unconsolidated silt overlaying a flat bedrock surface that showed high acoustic contrast and short wavelength roughness. By comparing comprehensive postsurvey dredging of the entire site with a prestack time-migrated 3D volume, it is possible to confirm a 100% detection rate for all discrete buried objects larger than 0.30ϫ 0.30 m in an illuminated area, although one acoustic anomaly could not be accounted for in the dredging results.

show abstract

“…This is necessary because the receiver positions are not explicitly known. Schock et al (2001) describe a buried object scanning sonar that uses a chirp source.…”

Section: Introductionmentioning

confidence: 99%

Design of a 3D Chirp Sub-bottom Imaging System

et al. 2005

View full text Add to dashboard Cite

Chirp sub-bottom profilers are marine acoustic devices that use a known and repeatable source signature (1 -24 kHz) to produce decimetre vertical resolution cross-sections of the subseabed. Here the design and development of the first true 3D Chirp system is described. When developing the design, critical factors that had to be considered included spatial aliasing, and precise positioning of sources and receivers. Full 3D numerical modelling of the combined source and receiver directivity was completed to determine optimal source and receiver geometries. The design incorporates 4 source transducers (1.5 -13 kHz) that can be arranged into different configurations, including Maltese Cross, a square and two separated pairs. The receive array comprises 240 hydrophones in 60 groups whose group-centres are separated by 25 cm in both horizontal directions, with each hydrophone group containing four individual elements and a pre-amplifier.After careful consideration, it was concluded that the only way to determine with sufficient accuracy the source-receiver geometry, was to fix the sources and receivers within a rigid array.Positional information for the array is given by a Real Time Kinematic GPS and attitude system incorporating four antennas to give position, heading, pitch and roll. It is shown that this system offers vertical positioning accuracy with a root-mean-square (rms) error less than 2.6 cm, while the horizontal positioning rms error was less than 2.0 cm. The system is configured so that the chirp source signature can be chosen by software aboard the acquisition vessel. The complete system is described and initial navigational and seismic data results are presented. These data demonstrate that the approach of using a fixed source-receiver geometry combined with RTK navigation will provide complete 3D imaging of the sub-surface.3

show abstract

Buried object scanning sonar

Cited by 57 publications

References 9 publications

Buried Underwater Object Classification Using a Collaborative Multiaspect Classifier

Buried Underwater Object Classification Using a Collaborative Multiaspect Classifier

Decimeter-resolution 3D seismic volume in shallow water: A case study in small-object detection

Design of a 3D Chirp Sub-bottom Imaging System

Contact Info

Product

Resources

About