RTK River Bathymetry in Africa

From Syledis and Tide Gauge to RTK GPS Water-level Corrected Survey
This article describes the installation of a hardware and software system for bathymetric surveys in the maritime part of the Congo River. The ‘Regie des Voies Maritimes’ (RVM) is a Congolese public administration in charge of an operational navigation river lane in the Congo maritime reach. The Congo River has the second lar­gest flow in the world and is 4,700km long. RVM maintains the conditions for commercial navigation in the so-called ‘maritime area’, from the mouth to Matadi harbour, over a distance of 150km. The estuary is the only maritime border of the Democratic Republic of the Congo (DRC), with... (read more)
2007-11-27 12:00:00

Shallow Survey 2005 Common Dataset Comparisons

Shallow Survey 2005 Common Dataset Comparisons As part of the Shallow Survey Conference 2005 held in Plymouth, swath sonar manufacturers were invited to survey a common dataset. Two regions were chosen: an offshore area south of Plymouth breakwater suited to larger vessels and Lidar operations, and an inshore area around Plymouth Hoe. The data collected for the inshore area serves as the basis for this study. The manufacturers and systems that provided data for the inshore area are listed in Table 1. Each of the surveys was undertaken with the same supporting equipment, and mostly using the same vessel. RTK... (read more)
2008-01-01 01:00:00

Hydrography Will Be Big Contributor Filling the Digital Aquarium

Hydro International Interviews Mathias Jonas, Secretary-General of the International Hydrographic Organisation
The new secretary-general of the International Hydrographic Organisation (IHO), Mathias Jonas, has had a long career, now culminating in the highest rank within the world’s leading organisation for hydrography. He took office this autumn, succeeding Robert Ward, after he was elected in spring this year by the Member States. 'Hydro International' of course wants to know what Dr Jonas envisions for hydrography and the wider world it influences. Mathias Jonas starts off by sharing how he was already in touch with IMO and IHO in the nineties. ‘Arriving at the German maritime administration as a young professional mariner and as one... (read more)
2017-12-05 01:50:23

The Dawn of the Digital Age

How digital visual systems lower costs and improve efficiency
Traditionally, Video Inspection surveys have been performed by ROV using analogue CCD colour cameras, with the video pictures recorded to S-VHS videotapes. This technology has served the industry well for more than twenty years but technology moves on: the world watches films on DVD, digital video movie trailers can be viewed over the internet and 3G mobile phones allow digital video clips to be viewed on the move. We are about to witness the same paradigm shift in the way we handle video information as occurred twelve years ago when CD audio replaced analogue vinyl recordings. Digital video systems offer... (read more)
2008-01-01 01:00:00

GNSS: Hydrographic Perspectives (Part 2)

Developments in GNSS, Possibilities for Hydrography
Hydro International Interviews Gary Chisholm, Trimble, Paul Cross, UCL, Owen Goodman, Fugro and Peter Grognard, Septentrio<br /> <br /> When Hydro International interviewed a group of experts on developments in GNSS as related to the hydrographic profession, they responded with such enthusiasm that that we were forced by lack of space to publish the interview in two parts. Part 1, which concentrated on the new opportunities offered the surveyor by horizontal and vertical accuracy and the need for differential solutions, appeared in our October issue. We now present the second part of the interview. Can you briefly explain the possibilities/advantages... (read more)
2008-01-01 01:00:00

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

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

‘Killer’ AUV Sonar System

In January 2001, C&C Technologies (C&C), a company based in Lafayette (Louisiana, USA), introduced the first commercially successful autonomous underwater vehicle (AUV) to the offshore industry. The AUV’s survey sensor suite, which included an EdgeTech side-scan sonar and sub-bottom profiler, performed well in the Gulf of Mexico and Brazilian offshore environments. However, West Africa proved more challenging – particularly for the sub-bottom profiler. C&C soon began searching for alternative technologies to provide better sub-bottom profiler penetration and higher resolution side-scan sonar imaging.Jim Chance, C&C Technologies (USA) Art Kleiner, EdgeTech (USA)<P> Narrator: Fast forward to the early autumn of 2004… C&C... (read more)
2008-04-02 12:00:00

Global Navigation Satellite Systems

Infrastructure Status and Developments
The concept of GNSS was first introduced by the European Space Agency (ESA), the European Commission (EC) and Eurocontrol in the early nineties. They defined requirements for a European GPS augmentation system, GNSS-1, and a full European satellite navigation system, GNSS-2, later together renamed EGNOS (European Geostationary Navigation Overlay System) and Galileo. Satellite navigation infrastructure status and developments are described here. Nowadays the term GNSS is used for the system of systems comprising GPS and GLONASS, with the later addition of Galileo. Satellite-based and ground-based augmentation systems (SBAS and GBAS) were introduced to augment GPS and GLONASS. Hydrographers were early... (read more)
2008-01-01 01:00:00
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