12.75" Synthetic Aperture Sonar (SAS), High Resolution and Automatic Target Recognition

Matthews, Anthony D.; Montgomery, Thomas C.; Cook, Daniel; Oeschger, John; Stroud, John S.

doi:10.1109/oceans.2006.307046

Cited by 8 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The phase center approximation assumes the sensed scene is in the far field of the Vernier array formed by the projector and multiple receivers. Many early research SAS sensors deployed small receive arrays [12][13][14], and the phase center approximation holds across the entire imaging swath for these sensors. More recently developed commercial systems are deploying large receive arrays, and in some cases, these arrays are up to three meters in length [15].…”

Section: Spatial Coherence Considerations For the Phase Center Approx...mentioning

confidence: 99%

Spatial coherence considerations for the phase center approximation

Brown

Blanford

2023

Preprint

View full text Add to dashboard Cite

Synthetic aperture sonar image reconstruction relies on the coherence of overlapping phase centers to provide accurate micronavigation for a sensed scene. It is shown that phase centers lose coherence for near-range scattering from large SAS arrays due to the fundamentally bistatic nature of these sensors. This effect is modeled using the van Cittert-Zernike theorem and a point-based sonar scattering model. Reduction of the window length used in the delay estimation process can partially mitigate the loss of coherence at the expense of increased variance in the resulting delay estimates.

show abstract

Section: Spatial Coherence Considerations For the Phase Center Approx...mentioning

confidence: 99%

Spatial coherence considerations for the phase center approximation

Brown

Blanford

2023

Preprint

View full text Add to dashboard Cite

show abstract

“…In this section, we investigate a small subset of the variables that contribute to the contrast ratio of a representative highfrequency SAS system. The parameters used are given in Table IV and they are based loosely on the SAS12 system developed under the sponsorship of the Office of Naval Research by the Naval Surface Warfare Center -Panama City Division and the Applied Research Laboratory at The Pennsylvania State University [12]. The beampatterns are assumed to be sinc functions, which depend only on the transducer dimensions and the wavelength.…”

Section: B Application To a Representative Sas Designmentioning

confidence: 99%

Analysis of Shadow Contrast for Synthetic Aperture Sonar Imagery

COOK,

BROWN

2023

Synthetic Aperture Sonar and Radar 2010

View full text Add to dashboard Cite

The contrast, or depth of shadows, in synthetic aperture sonar (SAS) imagery is arguably as important to image interpretation as the focus of the backscattered returns. The maximum contrast that can be achieved is determined by a combination of hardware, software, and environmental parameters. In this paper, the impact of these parameters on shadow contrast is quantified, and the contrast ratio is developed as a metric to predict a system's capacity to form imagery with well-defined shadows. A representative SAS is described, and its contrast ratio is investigated over a limited set of environmental and hardware parameters. This contrast ratio analysis can serve a tool for predicting system performance, determining the best dynamic range for display, and bounding the effects of manufacturing tolerances and motion errors.

show abstract

“…AUVs with inherently steady motion and high-performance inertial navigation sensors are ideal platforms for SAS systems and are starting to become commercially available for survey work. Figure 2 shows a comparison between a 900 kHz conventional side scan and data collected using the 180 kHz SAS12 system [34] during the AUVfest 2008 trials. The SAS12 system has a nominal resolution of 2.5 cm62.5 cm and was designed as a mine-hunting tool for proud and partially buried objects.…”

Section: Large-area Searchesmentioning

confidence: 99%

Autonomous Underwater Vehicles as Tools for Deep-Submergence Archaeology

Roman

Mather

2010

Proceedings of the Institution of Mechanical Engineers, Part M:

View full text Add to dashboard Cite

Marine archaeology beyond the capabilities of scuba divers is a technologically enabled field. The tool suite includes ship-based systems such as towed side-scan sonars and remotely operated vehicles, and more recently free-swimming autonomous underwater vehicles (AUVs). Each of these platforms has various imaging and mapping capabilities appropriate for specific scales and tasks. Broadly speaking, AUVs are becoming effective tools for locating, identifying, and surveying archaeological sites. This paper discusses the role of AUVs in this suite of tools, outlines some specific design criteria necessary to maximize their utility in the field, and presents directions for future developments. Results are presented for a recent joint AUV-towed system survey and a demonstration of current mine-hunting technologies applied to archaeology.

show abstract

12.75" Synthetic Aperture Sonar (SAS), High Resolution and Automatic Target Recognition

Cited by 8 publications

References 0 publications

Spatial coherence considerations for the phase center approximation

Spatial coherence considerations for the phase center approximation

Analysis of Shadow Contrast for Synthetic Aperture Sonar Imagery

Autonomous Underwater Vehicles as Tools for Deep-Submergence Archaeology

Contact Info

Product

Resources

About