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

Small Boat Work – Dangerous Then, Dangerous Today

The ability to conduct inshore hydrographic surveys has always been dependent on small boats and the seamanship of those conducting the surveys. Besides the obvious use of small boats for the acquisition of soundings and their accompanying positions, it was not so long ago that many surveys of remote and open coastlines also had to transport topographic and geodetic survey crews to shore camps or daily work areas. Although the nature of both shore work and hydrographic work has changed somewhat over the years, small boat work with its attendant dangers has remained a constant. Before the days of radio... (read more)
2016-09-27 04:24:02

Underwater Noise Monitoring in the North Sea

Jomopans Project to Monitor Continuous Sound
Sound is of vital importance for marine animals. Eleven institutes from the countries bordering the North Sea have joined forces in the Jomopans project to implement a novel monitoring strategy for underwater sound. Due to the growth of human activities in the sea, sound pollution is a growing concern for marine environmental managers. High levels of anthropogenic noise disturb animals, but the integrated impact of noise on the marine ecosystem is largely unknown. In the Joint Monitoring Programme of Ambient Noise in the North Sea (Jomopans) project, measurements at sea are combined with noise maps from numerical modeling to assess the quantitative levels of sound at sea. Sound is of vital importance for marine animals. Eleven institutes from the countries bordering the North Sea have joined forces in the Jomopans project to implement a novel monitoring strategy for underwater sound. Due to the growth of human activities in the sea, sound pollution is a growing concern for marine environmental managers. High levels of anthropogenic noise disturb animals, but the integrated impact of noise on the marine ecosystem is largely unknown. In the Joint Monitoring Programme of Ambient Noise in the North Sea (Jomopans) project, measurements at sea are combined with noise maps from numerical modeling to assess... (read more)
2019-06-18 04:01:43

Businesswoman in the Middle East

Interview with Susan Murray, General Manager of the Seatronics’ Middle East office
Ms Murray joined Oceonics (the forerunner of Seatronics) in 1981. It was here that she got her first taste of business in the hydrographic Industry, specifically in the sales environment. After spending a couple of years gaining valuable experience with another equipment rental company in Aberdeen, she returned to Oceonics as Sales Manager. Between 1987 and 1996 she was the General Manager of her own equipment rental company in Aberdeen, selling this in 1996. In 2000 she decided it was time to move on and, believing herself too young to retire, agreed to take on the role of Middle East... (read more)
2008-01-01 01:00:00

DHN's Contribution to Olympic and Paralympic Games in Rio 2016

DHN Chosen to Aid Olympic Water Sports
Hosting the Olympic Games includes supporting water-sports competitions like sailing, swimming marathons and triathlons. The Brazilian Directorate of Hydrography and Navigation (DHN) has been supporting Olympic sailing and other international yachting races since Athens 2004, in addition to being the accredited organisation to provide safety in Brazilian waters and a large portion of the South Atlantic Ocean. As a result, the Rio 2016 Organizing Committee selected DHN to add expert weather forecasting and to deploy metocean buoys  to collect data to support water sports during the recent Olympic and Paralympic Games. The Directorate of Hydrography and Navigation (DHN) is accredited in... (read more)
2016-10-10 03:38:17

Creating 'The World'

Surveying the longest breakwater ever constructed
Who hasn’t heard of the mega projects currently being executed in Dubai? Land reclamation projects that can be seen from space and skyscrapers that reach 800 meters high are not unusual for the Emirate. Van Oord Dredging and Marine Contractors is working amongst others on the construction of 300 artificial islands that form the map of the world. The configuration measures seven by nine kilometres and is protected by 5 breakwaters with a total length that exceeds 25 kilometres, the longest ever constructed. 'The World' is an archipelago of over 300 artificial islands that forms a map of the continents... (read more)
2008-01-01 01:00:00

Off-the-shelf Surveying Beyond 200 Miles

A contractor’s flexible approach to Art. 76-related surveys
The unique opportunity now open to Coastal States to extend their maritime boundaries seawards has led to great interest in the particular marine geophysical and hydrographic survey techniques required to collect additional data in support of continental shelf extension. Criteria laid down in the United Nations Convention on the Law of the Sea (Art. 76, UNCLOS) emphasise each nation being able to "…establish the outer limits of the continental margin wherever the margin extends beyond 200 nautical miles…" (www.un.org/Depts/los/index.htm). We describe Gardline’s experience with specific reference to surveying the continental margin of the Republic of Namibia. The objectives associated with... (read more)
2008-01-01 01:00:00

No More Spatial ­Misinterpretation Using Different Technologies

Capturing an Entire Maltese Islands’ Territory
Malta, the smallest European Union state, has carried out a country-wide hydrographic survey which was initiated in Q1 2012 and completed in Q4 of the same year. Aimed at acquiring baseline information that satisfies a number of key National and European Directives including the Water Framework Directive, the central Mediterranean state took the ambitious step of employing different technologies within one project in order to ensure compliance. An inability to collect base physical data on which to build reliable thematic environmental data would not only make Malta more exposed to various environmental pressures due to poorly informed policy decisions, but... (read more)
2013-01-18 02:49:01

HURRICANE!

North Atlantic hurricane season is now upon us. Until well into the twentieth century there was little understanding of the nature of hurricanes and no adequate system to warn mariners of these dangerous storms. This often led to disaster. The following is an incident affecting a pioneering oceanographic ship conducting Gulf Stream studies. North Atlantic hurricane season is now upon us. Until well into the twentieth century there was little understanding of the nature of hurricanes and no adequate system to warn mariners of these dangerous storms. This often led to disaster. The following is an incident affecting a pioneering... (read more)
2013-07-12 01:56:33

Mapping the Floor of Upper Loch Linnhe Using AUVs

Due to their particularly shallow and turbulent thermocline, conducting seafloor mapping in lochs, fjords and other estuaries always presents a unique challenge to the hydrographic surveyor. Surface vessels often struggle to obtain accurate measurements due to the highly variable impedance of an estuary’s mixing layer, which causes frequent and significant changes in the salinity (and, by extension, density and temperature) of the brackish water. These rapid changes in the sound velocity of the mixing layer introduce a refraction error as sonar travels through the medium, and this error is extremely difficult to account for. This effect is especially prominent in... (read more)
2015-01-29 03:16:23
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