Versatile Side-scan Sonar

JW Fishers developed a side-scan towfish with adjustable transducers. The angle of the transducers can be changed by rotating the tail section of the towfish. This allows the sonar to scan the hull of a ship for attached contraband compartments and inspect the face of a dam, bridge, or oil platform for explosive devices. Already several departments have purchased these side scans with the new adjustable transducers including the Escambia Sheriff’s Office in Pensacola (FL, USA) and the Washington County Sheriff’s Office in Stillwater (MI, USA). Jim Anderson of Washington County’s Water Recovery Unit says to be impressed with the... (read more)

2008-07-02 09:17:29

Multibeam Sonar Training Course

The 51st UNB-OMB / UNH-CCOM Multibeam Sonar Training Course, co-hosted by the Directorate of Hydrography and Navigation, Brazilian Navy, will be held from 23-28 November 2009 at the Hotel Orizzonte, Niterói, RJ, Brazil and this will be first time the course has been conducted in South America. The Multibeam Course is a 36-lecture, 6-day course primarily designed to provide a theoretical and practical background in marine multibeam survey technology and techniques. The information is tailored for those using marine multibeam survey systems in both the traditional hydrographic survey field (for safety of navigation and nautical charting) as well... (read more)

2009-10-19 10:14:45

Synthetic Aperture Sonar Challenges

Synthetic aperture sonar (SAS) has been under active development for decades. The technique is particularly well suited for autonomous underwater vehicles, and it is expected that SAS will replace traditional side-scan sonars for many ‘high-end’ AUV applications in the years to come. Research systems have been used for more than 15 years and many R&D groups around the world have been able to present images that would not have been possible to produce using traditional sonars. However, in many cases, these impressive sonar images are the result of days of tuning and tweaking by experts. A lot of effort has... (read more)

2008-05-15 12:00:00

Edgetech Sonar Demonstrated

EdgeTech is to demonstrate the latest technology in side-scan sonar and swath bathymetry at the upcoming US Hydro 2011 Conference in Tampa, Florida, from 25th to 28th April. EdgeTech's vessel, the Ocean Research II, will be outfitted with various equipment. EdgeTech's 4600 combines the high resolution 2D capabilities of a side-scan sonar with the 3D imagery of a multi-beam echo sounder. The result is a highly effective survey tool that produces real-time high resolution 3D maps of the seafloor and is simple to use and cost-effective. The 4200 is EdgeTech's most versatile side-scan sonar system and can be configured for... (read more)

2011-03-04 12:00:00

Successful Sonar Software Workshop

Chesapeake Technology recently hosted over 63 professionals for a hands-on training seminar focusing on the use of sidescan and sub-bottom sonar software. The three-day event held in the Charleston (South Carolina, USA) area was CTI's third annual workshop for underwater survey professionals. The training included two four-hour sessions aboard the Silver Crescent, a research vessel provided by South Carolina's Department of Natural Resources. As the participants experienced the field exercise aboard the Silver Crescent, the ship simultaneously towed two sidescan sonars. Both systems, a Klein System 3900 (courtesy of L-3 Klein) and a Marine Sonic Sea Scan PC system... (read more)

2008-01-14 10:51:25

Acoustic Classification by Sonar

Disparate approach successful in cost-effective mapping

A breakthrough in signal conditioning has lead to significant improvements in single-beam and swath classification. With modern computers, this allows cost-effective bottom classification across multiple sonar platforms. The common dataset generated as a result of the highly successful shallow-survey conferences sponsored by the University of New Hampshire Ocean Mapping Group and the Defence Scientific and Technical Organisation of Australia is an ideal proving ground for classifying the same seabed using multiple platforms. The results of processing and classifying a common dataset are presented in this article. Acoustic seabed classification is in wide use for applications from habitat mapping to mine... (read more)

2008-01-01 01:00:00

Sonar Uncertainty Instrument

L-3 Klein (USA) is to present the HydroChart 5000 (HC5000) Sonar Uncertainty Model at the upcoming Shallow Survey 2012 Conference to be held in Wellington, New Zealand, from 20th to 24th February 2012. The HC5000 is a portable, high-speed hydrographic survey system able to simultaneously collect IHO-quality bathymetry and co-registered, high-resolution, multi-beam side scan sonar data. In order to qualify the system for use in hydrographic survey, L-3 Klein developed an uncertainty model which makes use of existing theoretical models of acoustic propagation, bottom and surface scattering, array processing, bathymetry signal processing, and statistical processing. This model was statistically... (read more)

2012-01-17 02:18:25

Multibeam Sonar Training Course

This comprehensive six-day course is designed to provide a theoretical and practical background in multibeam survey technology and techniques for hydrographic surveys, continental shelf boundary delimitation, offshore engineering, harbor dredging, fisheries habitat, route survey and scientific research, and provides overviews of: • the technology and problems associated with shallow water multibeam surveys,• processing and visualization techniques designed to address the complexities of swath mapping, • constraints on using swath bathymetry to produce highest quality data. (read more)

2016-09-12 11:13:49

Sonar in Fisheries Research

A year round study on fish migration

Fisheries acoustics has its origin in the marine environment. Only with the development of small elliptical beams has it become possible to apply sonar in shallow freshwater. Since 1992 the Organisation for the Improvement of Inland Fisheries uses sonar for fisheries research, in The Netherlands. The mean application of sonar in freshwater is fish stock assessment by means of a mobile survey. In addition, sonar equipment can be applied at a fixed location to study fish migration. This gives information on the exact timing, direction and relative number of migrating fish over time. To be sure of the absolute number,... (read more)

2008-01-01 01:00:00

3D Sonar Technology

The journey from oil and gas to homeland security and back again

Since its introduction many years ago, survey sonar has evolved steadily, but is still a difficult and non-intuitive survey tool, requiring large amounts of processing to arrive at the most basic end product. Initially, anyone wanting to survey or inspect the underwater environment was limited to single beam echo-sounders, in simple terms one-dimensional sonar, yielding very little quantifiable data. These in turn were developed into mechanically scanned sonars, and subsequently into today’s high performance multi-beam and forward looking sonars which are the back-bone of the survey industry. Even the very best commercially available multi-beam sonar delivers only 2 dimensional data... (read more)

2008-01-01 01:00:00