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

Technology for Hydrographic Purposes

Interview with Erik Hammerstad, Kongsberg Maritime AS
Hardware (and to a lesser extent software) for the hydrographic survey industry is mostly developed by technical experts not educated as hydrographic surveyors. Nevertheless, manufacturers have come up with equipment that has broadened and hugely opened up the possibilities for hydrographic and oceanographic investigations. What is the link between hydrography, which still very much depends on field experience, and technological developments? Or how is technology directed towards the invention of usable and workable equipment for hydrography? Hydro international interviewed Erik Hammerstad, Senior Principal Engineer /Hydrography Subsea of Kongsberg Maritime AS Norway. Please tell our readers something of your professional education... (read more)
2008-01-01 01:00:00

Echo Sounders versus Air Bubbles in Research Vessels

Lessons from Experience
Within echo sounding circles it is well known that air bubbles may have a negative effect on echo sounding systems. This article briefly presents the German way of dealing with air bubbles from sweep-down and cavitation processes as well as our experiences with the last three large research vessels (RVs Polarstern, Meteor and Maria S. Merian). The practical experience resulted in the development of an optimised new hull form for the replacement of RV Sonne. The new ship is now under construction at a German shipyard and will be delivered in autumn 2014. The basis of all echo sounding systems... (read more)
2014-02-27 03:37:56

The Advancing Technology of AUVs

A View of the Autonomous Underwater Vehicle Market
Since the last autonomous underwater vehicle (AUV) review in 2016, the market has continued to grow. The biggest market for AUV systems remains the military. The world’s most advanced Navies own and operate low-logistic AUV systems for mine countermeasures (MCM) in very shallow waters. These systems can operate in confined areas where MCM vessels cannot. The same systems can also be used in search and recovery operations, hydrography and salvage. This market used to be dominated by a handful of AUV providers. However, the number of manufacturers is increasing. Defence primes are also investing in these technologies through internal development... (read more)
2018-12-04 09:23:07

Excited by Automation Driven by Autonomous Vehicles

Hydro International Interviews Capt. Shep Smith
NOAA is one of the bigger organisations in the world that has surveying and charting in its portfolio. It’s an immense task as the USA has about 95,000 miles of coastline, important ports and a wide range of users – from recreational boaters to the biggest container vessels and tankers. The country also has to deal with environmental disasters like hurricanes and oil spills. NOAA is undergoing changes as the chart portfolio is ‘going digital’ and new initiatives such as using Maritime Autonomous Systems (MAS) for surveys. Hydro International interviews Capt Shep Smith, who generously gave an insight behind the scenes. NOAA is one of the bigger organisations in the world that has surveying and charting in its portfolio. It’s an immense task as the USA has about 95,000 miles of coastline, important ports and a wide range of users – from recreational boaters to the biggest container vessels and tankers. The country also has to deal with environmental disasters like hurricanes and oil spills. NOAA is undergoing changes as the chart portfolio is ‘going digital’ and new initiatives such as using Maritime Autonomous Systems (MAS) for surveys. Hydro International has interviewed Capt Shep Smith, who generously gave an insight behind... (read more)
2015-12-01 09:18:32

Low-budget Hydrography

Opinions from differing backgrounds
Low-budget Hydrography is the theme of this issue. Realising that different players in hydrography will have differing opinions on various aspects of low-budget hydrography and interested in exploring these divergent views on your behalf, HI asked representatives from various camps for their opinions on some leading questions. The representatives interviewed are: Jeffrey F. Marlow, Survey Technician, US Army Corps of Engineers CDR Guy Noll, Commanding Officer, NOAA Ship RAINIER LTCDR Richard Cullen, Staff Officer Quality Control AHS Questions: 1. Can you briefly explain your position in the hydrographic world: your experience and present position? Cullen: I have been employed by... (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

Capturing Convection: Glider Validated Modelling

Can Underwater Gliders Be Used to Check Ocean Forecast Accuracy?
Recently, three unmanned underwater vehicles (UUVs) were deployed in the northwest Mediterranean Sea to monitor open-ocean convection via changes in the local density structure. Mixed-layer depth and thermocline response to buoyancy flux were extrapolated from in-situ profiles and used to infer the occurrence of deepwater formation events. The high-resolution data set acquired has been used to assess ocean forecast model performance in this area. The advantages of employing glider data sets in further validation schemes are discussed here. Forecast models are employed by the oceanographic agencies for meteorological and commercial shipping applications, as well as in naval sonar propagation studies,... (read more)
2010-07-12 04:21:48

Exploring the Deepest Points on Planet Earth

Report on The Five Deeps Expedition
As extreme explorer Victor Vescovo continues his round-the-world expedition to become the first person to descend to the five deepest points in the Earth’s five oceans using the custom-built deep submergence vehicle Limiting Factor, it prompts the question: ‘Do we know as much about the deepest places on our planet as we thought?’ As extreme explorer Victor Vescovo continues his round-the-world expedition to become the first person to descend to the five deepest points in the Earth’s five oceans using the custom-built deep submergence vehicle Limiting Factor, it prompts the question: ‘Do we know as much about the deepest places on our planet as we thought?’ Today, the best global maps of the oceans have a resolution of 30 arc-second grid cells (926m at the equator). Approximately 82% of the grid cells do not include a single depth measurement (Weatherall et al., 2015), and the percentage of the seafloor that has been directly... (read more)
2019-06-18 03:32:12

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
Search Filter