Lidar Bathymetry on the Alaskan North Slope

Inventory and Characterisation of More than 4,500 Shallow-water Bodies
In June 2014, the Bureau of Economic Geology, a research unit at the University of Texas at Austin, was contracted to conduct an airborne bathymetric Lidar survey on the Alaskan North Slope. The purpose of the project was to further determine, understand, and map the local landscape and thaw-lake attributes of an area west of the Dalton Highway and Sagavanirktok (Sag) River, approximately 30km southwest of Deadhorse, Alaska. Researchers from the Bureau had visited the area in 2012 and found bathymetric Light Detection and Ranging (Lidar) to be an effective tool for measuring the area’s lakes. The group returned in... (read more)
2016-04-04 10:08:41

Riverbed Surveying

Hydromapping - High Resolution Shallow Water Mapping from an Airborne Platform
In order to meet the requirements of the European Water Framework Directive (EU-WFD), authorities face the problem of performing area-wide surveys of all kinds of inland waters repeatedly. Especially for mid-sized and small rivers, a traditional survey approach imposes almost insurmountable logistical efforts and costs. Employing the new airborne hydrographic laser scanner RIEGL VQ-820-G, potential large-scale surveying of a river system is exemplarily demonstrated on the river Loisach in southern Germany, carried out by the company AirborneHydroMapping (AHM) and the University of Innsbruck. By Martin Pfennigbauer, RIEGL, and Frank Steinbacher, University of Innsbruck, Austria. In co-operation with the Bavarian Water... (read more)
2012-03-08 04:33:36

Improving Uncertainty Visualisation in ENCs

Towards a Better Portrayal of Bathymetric Data Quality for Mariners
The visualisation of bathymetric data and associated uncertainty in electronic nautical charts (ENCs) is important when it comes to planning and monitoring a ship’s route safely. However, a study confirmed that the current uncertainty representation is not very intuitive and does not provide clear orientation for mariners. To improve this situation, Fraunhofer IGD proposed novel visualisation solutions for the next-generation S-101 ENC standard. Read on for a summary. Electronic nautical charts (ENCs) are common tools for safe navigation at sea. By providing information concerning water as depth zones, contours and spot soundings, they support mariners in planning routes, which maintain... (read more)
2017-02-01 09:33:04

Hydrographic Use of Satellite Imagery in South Pacific

The French Hydrographic Office (SHOM) uses remotely sensed visible imagery for the cartography of atolls and reefs. It is considered as an efficient and relatively inexpensive method to collect information where data is sparse. Remotely sensed visible imagery is used in Pacific French Overseas territories for the cartography of atolls, reefs et cetera. All shallow-water areas may be involved, in particular when the cost of usual hydrography would be out of proportion with maritime traffic. Remotely sensed imagery is mixed with all field information available (bathymetry, buoys, seamarks) and a ‘spatiocarte’ (spatio-chart) is produced, which provides information on: Land: coastline,... (read more)
2008-01-01 01:00:00

Citizen Mapping and Charting (part 2)

How Crowdsourcing is Helping to Revolutionise Mapping & Charting
Part 1 of ‘Citizen Mapping and Charting' described the concept of crowdsourcing with examples. From here part 2 will focus on maps and charts. Everybody's a Map Maker The applications mentioned in Part 1 all make extensive use of spatial data and use map applications to display their results. Some (such as website 1 and the AIR (Area's Immediate Reading) project website 2) use graphical displays that most public institutions could only dream about - clearly a benefit from having one or two design students on your team of volunteers. The crowd makes extensive use of maps for display purposes... (read more)
2009-10-05 10:33:27

Searching for HMS Terror

Knowledge Gained in the Search for Franklin
“We know where the target is not located” is the only guaranteed result of any search expedition. This statement does not make for exciting headlines, however, the value of knowledge gained during the search itself and its many benefits to a variety of end-users, cannot be easily dismissed. The 2015 Franklin Expedition search coordinated by Parks Canada was the continuing multi-year, multi-partner effort that saw the discovery of HMS Erebus in September of 2014. In this article we will discuss the knowledge gained and multiple uses of the data collected toward our conclusion of verifying where HMS Terror is not... (read more)
2016-04-04 09:52:54

Robert Ballard: Exploring Human History Lost Beneath the Sea

Manned and unmanned underwater vehicles have been used for many years to explore the hidden features of the deep ocean. Dr Robert D. Ballard is an oceanographer most noted for his deep-ocean explorations for underwater archaeology. Ballard is best known for his discovery of the legendaryTitanicand underwater explorations of theBismarck,LusitaniaandBritannic. Hydrointernationalasks him about his experience and best practices when setting up explorations for human history lost beneath the sea.<P>     Please introduce yourself to our readers. I am an oceanographer who spent 30 years at the Woods Hole Oceanographic Institution (WHOI) where I studied ‘Plate tectonics and the volcanic,... (read more)
2008-07-04 12:00:00

Developments and Trends in Multibeam Echo Sounders

The multibeam echo sounders available on the market are constantly evolving as technology advances and as sonar producers seek new ways of refining and utilising the products. In this article we will provide a snapshot of current products and trends from the dominant (high-end) sonar producers focused on survey-grade products. Trend #1 – Resolution The neverending trend of getting higher resolution sonar systems is battling the physics of acoustics. Over the past several years, the battle for best-in-class multibeam for medium water depth has been between the Teledyne RESON SeaBat 7125, the Kongsberg EM 2040/2040C and the R2Sonic Sonic 2024.... (read more)
2016-02-01 03:59:24

Geophysical Surveys in West Africa

Detailed marine geophysical surveys are considered a key element in the process of development and construction of new offshore ports and load-out facilities. Specifically, seismic data constitute an essential part as they can reveal many unknown factors. Due to the challenging environment in West Africa and the often very shallow water depths, it requires a flexible and versatile approach from a survey company. This article gives an overview of how this type of project is approached and some of the lessons we have learnt when performing marine geophysical surveys in shallow water in West Africa.<P> West Africa is rich inmineral... (read more)
2009-01-05 12:00:00

Mapping the Seafloor with Remote Sensing and Satellite Imagery

An Analysis of the Techniques and Benefits of These Methods
70% of the Earth is covered by water, but so far just 7% of it has been surveyed (Mars, Venus and the Moon are better surveyed). Hydrography as a science has changed dramatically since the first measurements were made by Alexander Dalrymple and James Cook with lead lines and sextants. Singlebeam echosounders were invented in the 1920s – a technology still used today for mapping the seafloor. This method of using echosounders can produce very high-resolution bathymetric data but the high operational costs and the slow working process make it economically unsuitable for covering large areas. However, with the ongoing expenses of... (read more)
2018-06-19 09:23:54
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