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

Seamless Digital Hydrographic Data

Compiling digital smooth sheets using standard software
In line with developments in survey equipment, Japan Hydrographic and Oceanographic Department (JHOD) has constructed a new stream of digital hydrographic data that allows smooth transfer from survey vessel to ENC through newly designed ‘digital smooth sheets’. The author reviews the evolution of this GIS-based compilation system. In 1998 JHOD imposed the compilation of digital smooth sheets (including digital wharf-frontage sounding sheets) on hydrographic surveys. Conventional paper-based (or plastic-sheet-based) smooth sheets compiled manually from analogue hydrographic data have since been replaced by digital smooth sheets compiled on a Geographic Information System (GIS) from digitally obtained hydrographic data. For many years... (read more)
2008-01-01 01:00:00

Invited Reply

Hydrography or Hydrogeomatics?
In common with all sciences, hydrography too is undergoing rapid change with regard to data acquisition and processing, instrumentation, application and many other aspects. Differing ideas may be found within the hydrographic community concerning these developments, which direction to take, change in the nature of the science, etc. and some opinions are to some extent controversial. Hydro international would like to draw attention to such diverse opinions when and in whatever context they arise by modifying her traditional interview in this issue by a column entitled ‘Invited Reply’. The pertinent question will here be answered by six prominent figures from... (read more)
2008-01-01 01:00:00

George Belknap and the Thomson Sounding Machine

Prior to the year 1874, the Pacific Ocean was a blank slate with regard to the nature and depths of its seafloor. A few sporadic soundings had been attempted in the 1850s and Alexander Dallas Bache, Superintendent of the US Coast Survey, had derived an average depth for the North Pacific Ocean of 2,000 fathoms from tidal marigrams that had recorded the tsunami signature of the great 1854 Japanese Tokai earthquake. This in itself was a remarkable feat but provided no indication of the nature of the seafloor and the location of individual bathymetric features. However, this was about to... (read more)
2014-04-07 01:14:02

Computer-aided Paper Chart Production in Japan

‘Was all of this produced with the computer system?’
The Japan Hydrographic Department began developing a computer-aided production process about twenty years ago, but this proved difficult due to limitations in computer technology. Subsequent progress in this area has helped development of a computer-aided chart compilation method, resulting in unimagined improvements in efficiency. This article describes events of the past twenty years. Because of their indispensability for maritime navigation it is important that navigational charts be produced within as short a time period as possible and that their contents be constantly updated with the latest information. Despite this, the fact of most chart production processes being carried out by... (read more)
2008-01-01 01:00:00

Satellite-derived Bathymetry

A Reconaissance Tool for Hydrography
A study was conducted to evaluate the use of a satellite-derived bathymetry (SDB) procedure to map shallow-water bathymetry in a GIS environment, and to identify areas that require a new hydrographic survey. Publically available, multispectral satellite imagery and published algorithms are used to derive estimates of the bathymetry. The study results indicate a potential use of the procedure by national hydrographic offices as a reconnaissance tool. In some developing countries, the information available to plan and prioritise hydrographic surveys is typically based on visual inspection of existing nautical charts. However, due to the age of many existing charts and lack... (read more)
2013-12-04 11:21:17

Monitoring Marine Pollution

Detecting Offenders by Satellite in the Eastern Black Sea
An increase in marine traffic has recently been registered in the Black Sea, which is often accompanied by illegal oily water dumps, leaks during loading/off-loading operations and a higher risk of accidents. One of the primary tasks of ScanEx Research and Development Center is the operational satellite-based monitoring for real-time detection of oil spills and their sources. Repeat offenders of waste dumping and sources of pollution have been confidently identified, encouraging others to adopt a more responsible attitude towards the marine environment. View Larger Map According to statistics, transportation is the main source of world ocean pollution. This is also... (read more)
2009-05-12 12:00:00

The Making of RV 'Kronprins Haakon'

New Norwegian Ice-breaking Research Vessel
Norway is a maritime country with a very long coastline, plus it is very much a polar nation with 80% of its sea territory and 45% of its land mass north of the Arctic circle. It is the only country with territorial claims both in the Arctic and the Antarctic. In spite of this, Norway has not had a purpose-built polar research vessel since Roald Amundsen’s 'Maud' (1917), having instead relied on converted commercial vessels for such purposes. That has all changed, however, now that 'Kronprins Haakon' has come into service. This article provides insight into the making of this new multi-purpose research vessel.... (read more)
2018-04-17 10:51:23

Autonomous Underwater Vehicles

A View of the Autonomous Underwater Vehicle Market in 2016
This last year has seen an increase in Autonomous Underwater Vehicle (AUV) sales and prospects for new sales. The lower than usual oil price may be responsible for much of that growth. Faced with operating in an increasingly harsh market where cost efficiencies can be the difference between success or failure for a business, Oil and Gas companies have had to look for ways to operate profitably. This often means a fairly radical restructure of their business and operations. Survey class AUVs offer a level of technical and operational maturity at a price point that encourages their use by oil... (read more)
2016-07-26 11:26:42

An Early Search for Vigias

In the era before the global positioning system and other reliable navigation aids, many imaginary and sometimes real features whose positions were grossly in error were found on charts of the world’s oceans. This is the story of an early cruise devoted solely to expunging these features from charts of the Atlantic Ocean. “Vigia – A rock or shoal the existence or position of which is doubtful.” Such is the definition of this term in the glossary of the 1958 edition of theAmerican Practical Navigator. It might be added that at least 200 supposed islands were also classified as vigias... (read more)
2009-01-05 12:00:00
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