Self-installing Wind Turbines

A Different Approach
The Dutch company SPT developed a new foundation concept for offshore wind turbines in order to reduce the costs and environmental impact: a Self Installing Wind Turbine. The concept is based on a tripod with suction piles. As these foundations do not penetrate as deep as single pile structures, a different approach for survey and soil investigation techniques can be applied. Prior to the design of a wind farm, information on the seabed properties, its behaviour and the underlying geology are required. Insight into the morphology of the seabed by multi-beam (Figure 1), and side-scan sonar surveys (Figure 2) can... (read more)
2012-10-05 04:41:29

Altitude and Dynamic Error in TPE and CUBE

Total Propagated Error (TPE) and Combined Uncertainty Bathymetric Estimator (CUBE) help automate data cleaning and filtering. This paper discusses the effect of using altitude in place of heave for survey data processing and that of using error estimates in TPE and CUBE for both variables. Final hydrographic data quality is examined. Total Propagated Error (TPE) and Combined Uncertainty Bathymetric Estimator (CUBE) are designed for use with hydrographic survey data to minimise subjective user intervention and help automate data cleaning and filtering. With the trend in hydrographic surveying towards objective estimation of data quality, these methods rely heavily on error estimates... (read more)
2007-09-04 12:00:00

Refloating the Pasha Bulker

Hydrographic Survey Work to Assist the Salvage Operation
On Friday 8 June 2007, the bulk carrierPasha Bulkerran aground in heavy storm conditions on one of Newcastle’s most famous surfing beaches, Nobbys, near the entrance to Newcastle Harbour in New South Wales, Australia. As part of the large-scale salvage operation, the Survey Section of Newcastle Port Corporation and the Coastal Unit of the Department of Environment and Climate Change were called on to use their high-tech survey systems to provide bathymetry, navigation support and other services to the salvors. In the end, both departments made significant contributions to the success of the salvage operation. This article looks at the... (read more)
2007-11-27 12:00:00

Surveying and Charting

Hydro International Interviews Rear Admiral (R) Andres Roque Di Vincenzo
Surveying, charting and monitoring a complex and vast area which includes features from rivers, waterways, a long Atlantic coast to the Antarctic Peninsula environment, is a very challenging task. Only a well-equipped Governmental Hydrographic Institution can cope with it. The Servicio de Hidrografia Naval (SHN) of the Republic of Argentina, continuously produces the nautical information needed by sailors and the scientific world. In doing this, SHN benefits from its membership of the International Hydrographic Organization and of the Organisation of the Antarctic Treaty. Rear Admiral Di Vincenzo, who has headed the SHN for the past four years, explains how they... (read more)
2011-12-19 03:33:53

The Dutch Sector of the North Sea

A geological introduction
The North Sea directorate of the Ministry of Public Works and the department of Geo-Marine & Coast of The Netherlands Institute of Applied Geoscience-TNO jointly carried out a geological mapping programme and the assessment of industrial sand deposits in the Dutch sector of the North Sea. A brief outline of the methods used and the knowledge obtained is given. The Dutch part of the North Sea (NCP) occupies an area of 57,000 km2 which is larger than the mainland of The Netherlands (Figure 1). In addition to traditional activities, like fishery and shipping, since the 1960s there have been new... (read more)
2008-01-01 01:00:00

PPVRS Rushes in a New Era for Hydrographic Surveying

This paper describes a technique for centimetric positioning in hydrographic surveying using a network of GPS base stations to determine ephemeris, clock and atmospheric errors at the rover location. This technique uses the GPS observations from a Virtual Reference Station to compute a tightly integrated GPS/Inertial solution, with minimum baselines of over 100km.<P> Today’s primary positioningtechnique for near-shore (within 100km) marine hydrography is based on the integration of GPS and inertial navigation systems (INS). The inertial measurement unit (IMU) aids in reducing GPS noise as well as providing high-bandwidth uninterrupted solutions during GPS outages. For high-precision surveys (5cm or better... (read more)
2008-10-15 12:00:00

Supply Hydrographic Personnel

Hydro INTERNATIONAL Interviews Johan Stam, Business Development Manager, Atlas Services Group
There is a global shortage of hydrographic surveyors. The industry is faced with an interesting challenge and looks to specialised education facilities and personnel suppliers to assist in solving this problem. Even in times of high unemployment it can be difficult to find sufficient skilled personnel to carry out hydrographic survey work in the offshore environment. Hydrographic educational institutions around the world are struggling to attract enough students, resulting in noticeable shortages of trainees within the survey departments of large and small survey contracting companies. Although working conditions have improved considerably over recent decades, the environment in which hydrographic surveyors... (read more)
2008-01-01 01:00:00

Mariners Need More Current Hydrographic Data

Hydro International Interviews Rear Admiral Christian Andreasen, NOAA (Ret.)
Almost 50 years in hydrography gives you insight and authority to talk about the field and the changes it has gone through in half a century. Rear Admiral Christian Andreasen talks about his career. He is certainly not somebody who only looks back, but is still looking into the future, sharing strong ideas about where hydrography will need to go: ‘Mariners do not understand why hydrographic offices are not more supportive. Finding ways of providing mariners with more current data is an issue.’ Since the 1960s, when you became a hydrographer up to the present, the means and techniques for... (read more)
2012-06-06 03:35:09

Assessing the Quality of Soundings

Ensuring that your hydrographic data complies with the latest standards can be difficult, particularly as standards continually change with new advances in technology. Simon Squibb discusses a ‘binning’ technique that may improve data confidence for surveyors and clients. The standards for hydrographic measurements are regularly reviewed to cope with advances in technology and the demand for higher accuracy data, which continually increases. For example, last year the 4th edition of the international standard, IHO S44 (1), was modified by various hydrographic authorities to meet wider application. To aid their surveyors in assessing the quality of data collected, Andrews Survey has... (read more)
2008-01-01 01:00:00

Rheology as a Survey Tool

“We Are Not There Yet”
To reduce the dredging cost many harbour authorities and governmental bodies are seeking for a more suitable and a rheology-related survey tool. The in situ instruments available on the market are based on mechanical, acoustical, optical or radioactive measuring principles. But before one will be able to map the real nautical bottom, we need to understand the influence of the mud properties (micro scale) on a vessel (macro scale). This article gives an overview of the general reaction forces of the mud which definitely play an important role in the vessel behaviour when sailing into it. Without naming any commercial... (read more)
2011-05-17 03:42:46
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