An algebraic approach to synthetic aperture sonar image reconstruction

Silva, S.R.; Cunha, Sérgio; Matos, Aníbal; Cruz, Nuno

doi:10.1109/oceans.2008.5151974

Cited by 3 publications

(1 citation statement)

References 10 publications

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“…The image formation relies on a back-projection algorithm (Hunter et al, 2003;Shippey et al, 2005;Silva et al, 2007Silva et al, , 2008a. This class of synthetic aperture imaging algorithms, although quite computationally expensive in comparison with frequency domain algorithms, lends itself very well to non-straight acquisition trajectories and, therefore, to the inclusion of known motion deviations from the expected path.…”

Section: Image Formationmentioning

confidence: 99%

Shallow Water Surveying Using Experimental Interferometric Synthetic Aperture Sonar

Silva¹,

Cunha²,

Matos³

et al. 2009

mar technol soc j

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A B S T R A C TThis paper describes an interferometric synthetic aperture sonar system based on an unmanned surface vehicle customized for shallow water environments. Synthetic aperture sonar enables imagery of high resolution that is independent of range by using the displacement of the sonar platform to create a large virtual array. If two geometrically displaced images are obtained, the construction of threedimensional topographic maps is possible through the use of interferometric techniques. The use of an unmanned surface vehicle presents several advantages that alleviate some problems related to the formation of synthetic aperture images, which are mainly related to the fact that a precise navigation system can be used for the boat control and sonar imagery motion compensation. Also, a small unmanned surface vehicle is advantageous in terms of cost of operation, maintenance and ease of deployment. Mapping of shallow water areas is an important task for many commercial and scientific applications like river navigability, infrastructure maintenance and natural resource monitoring. These tasks can be done efficiently with this system. Sample data obtained during test trials illustrate how synthetic aperture can be used to generate underwater imagery and bathymetric data. A B S T R A C TThis paper describes an interferometric synthetic aperture sonar system based on an unmanned surface vehicle customized for shallow water environments. Synthetic aperture sonar enables imagery of high resolution that is independent of range by using the displacement of the sonar platform to create a large virtual array. If two geometrically displaced images are obtained, the construction of threedimensional topographic maps is possible through the use of interferometric techniques. The use of an unmanned surface vehicle presents several advantages that alleviate some problems related to the formation of synthetic aperture images, which are mainly related to the fact that a precise navigation system can be used for the boat control and sonar imagery motion compensation. Also, a small unmanned surface vehicle is advantageous in terms of cost of operation, maintenance and ease of deployment. Mapping of shallow water areas is an important task for many commercial and scientific applications like river navigability, infrastructure maintenance and natural resource monitoring. These tasks can be done efficiently with this system. Sample data obtained during test trials illustrate how synthetic aperture can be used to generate underwater imagery and bathymetric data.

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Section: Image Formationmentioning

confidence: 99%

Shallow Water Surveying Using Experimental Interferometric Synthetic Aperture Sonar

Silva¹,

Cunha²,

Matos³

et al. 2009

mar technol soc j

Self Cite

View full text Add to dashboard Cite

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Advances in Sonar Technology

Silva¹

2009

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The demand to explore the largest and also one of the richest part of our planet, the advances in signal processing promoted by an exponential growth in computation power and a thorough study of sound propagation in the underwater realm, lead to remarkable advances in sonar technology in the last years.Since the use of imaging system that rely on electromagnetic waves (optical, laser or radar) is restricted to only very shallow water environments, and given that the good propagation of sound waves in water is known from at least the writings of Leonardo da Vinci, the sonar (sound navigation and raging) systems are the most widespread solution for underwater remote sensing.Sonar systems can be divided into two major types: passive sonar systems that enable detection of a sound emitting target and active sonar systems that use the properties of a signal reflected on the targets for its detection and image formation.As system complexity increases, the study of the way sound is used to obtain reflectivity and bathymetry data from targets and submersed areas becomes fundamental in the performance prediction and development of innovative sonar systems.Because of the many similarities between sonar and radar, algorithms created for the latter found application in sonar systems which made use of the advances in signal processing to overcome the barriers of the problematic underwater propagation medium and to challenge the resolution limits. In particular, synthetic aperture methods, applied with so much success in radar imagery, were adapted to sonar systems. This in turn enabled a considerable increase in sonar image quality and system robustness. Target detection developments lead to the use of multiple transducer sensors and sophisticated beam forming techniques with also excellent results.High quality sonar imagery with reduced noise and enhanced resolution enables more complex applications. Leaving the traditional real of military applications, sonar civil applications arise for the study of biology ecology and related fields. Moreover integration and data fusion of different sensors is becoming more and more common, being it navigation data integration and enhancement for synthetic aperture, sonar systems with different propagation characteristics or optical image integration for the improvement of object detection.But, not unlike natural evolution, a technology that matured in the underwater environments is now being used to solve problems for robots that use the echoes from airacoustic signals to derive their sonar signals.The work on hand is a sum of knowledge of several authors that contributed in various different aspects of sonar technology. This book intends therefore to give a broad overview of the advances in sonar technology of the last years that resulted from the research effort of the authors in both sonar systems and its applications. It is destined to scientist and VIII engineers from a variety of backgrounds and, hopefully, even those that never had contact with sonar technology before will find an ...

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