Trends in Hydrography

Taking Lessons from Today's Technical Developments
It’s often a cliché to say that everything offshore has changed since the introduction of GPS, but there have certainly been many changes since back then in the 1980s. The other obvious transformational technology has been computers and computer processing that, like the rest of the world, has totally and radically changed our lives. It didn’t happen immediately of course – no, that would never do in the ultra conservative environment of hydrography and offshore surveying. However, it’s clear when comparing mid-20th century surveying with today that they have totally and fundamentally impacted our projects. Nowadays, such technologies are often taken... (read more)
2016-12-06 02:02:15

3D Sonar Technology

The journey from oil and gas to homeland security and back again
Since its introduction many years ago, survey sonar has evolved steadily, but is still a difficult and non-intuitive survey tool, requiring large amounts of processing to arrive at the most basic end product. Initially, anyone wanting to survey or inspect the underwater environment was limited to single beam echo-sounders, in simple terms one-dimensional sonar, yielding very little quantifiable data. These in turn were developed into mechanically scanned sonars, and subsequently into today’s high performance multi-beam and forward looking sonars which are the back-bone of the survey industry. Even the very best commercially available multi-beam sonar delivers only 2 dimensional data... (read more)
2008-01-01 01:00:00

Satellite-derived Bathymetry

A Reconaissance Tool for Hydrography
A study was conducted to evaluate the use of a satellite-derived bathymetry (SDB) procedure to map shallow-water bathymetry in a GIS environment, and to identify areas that require a new hydrographic survey. Publically available, multispectral satellite imagery and published algorithms are used to derive estimates of the bathymetry. The study results indicate a potential use of the procedure by national hydrographic offices as a reconnaissance tool. In some developing countries, the information available to plan and prioritise hydrographic surveys is typically based on visual inspection of existing nautical charts. However, due to the age of many existing charts and lack... (read more)
2013-12-04 11:21:17

From Papyrus to Electronic Charts

Modernising Fluvial Charts in the Amazon Region of Peru
The Amazon is the world’s largest river system. With more than 50,000km of navigable waters, ocean-going vessels are able to transit almost 6,000km from its mouth in the Atlantic Ocean to Iquitos, Peru. The Amazon and its more than 1,000 tributary rivers are characterised by rapid changes in water levels and current flow causing constant erosion and sedimentation. The need to continually monitor the location of river banks and channels presents an enormous challenge to those responsible for providing necessary hydrographic services to ensure safe fluvial navigation throughout the vast region. The Amazon River basin is approximately 7,050,000km2 in total... (read more)
2011-12-19 03:45:40

Technology in Focus: Insides of Side-scan Sonar

Advancing Technology for a Wide Range of Purposes
Although today’s multibeam echo sounders come with a backscatter option the more traditional Side-scan Sonar (SSS) still has many advantages when it comes to bottom imaging. Over the past years, SSS technology has gone through an evolution rather than a revolution. In this article we will zoom in on the current state of the art of this useful acoustic imaging device. Side-scan Sonar is mainly used for the detection of objects and bottom structures. To obtain those images it digitises a sound pulse sent out from two transducers mounted on each side of the SSS fish. Images are based on... (read more)
2016-05-19 01:22:38

Specifying a Waterside Facility Protection System

The problem of protecting ports, harbours and waterside facilities has recently received a great deal of attention. Several systems have been deployed, but almost none of these efforts has been totally successful. Here, we discuss some of the factors that can make the difference between success and failure when specifying a port protection system and the importance of the hydrographic environment. There are two types of systems. A permanently installed system (Figure 1) for initial intrusion detection and tracking, and a mobile system for entry route surveys, follow up and interception. The permanent systems require detailed hydrographic surveys for selecting... (read more)
2009-02-11 12:00:00

Unravelling the Mysteries of Venice

Use of side-scan sonar in underwater studies
The Venice Lagoon has been inhabited for over 1,300 years and the art and architecture of its city has been the subject of countless books and academic studies. Yet, despite this continuous scrutiny, virtually nothing has been known about the world beneath the surface of the lagoon. For centuries the hydraulic processes that fill and empty the 640sq km of the lagoon daily and the landscape of the seabed have been ignored or taken for granted. The threat created by rising sea levels has finally concentrated minds on finding a way of protecting the city’s treasures. Plans are being laid... (read more)
2008-01-01 01:00:00

Submarine Volcanoes and Autonomous Survey Vehicles

Fringed by deep trenches, Japan is a country composed of seismic and volcanic active island arcs, where the huge Pacific Plate and the smaller Philippine Sea Plate converge to the Eurasian Plate. Integration of tectonic and volcanic activity since the geological Tertiary period formed beautiful mountainous landscapes and scattered small plains with rich soil. At sea around Japan, two volcanic ridges are extending to south and southwest from the mainland Japan. It means Japanese waters are not free from volcanic hazards. In the morning of 17 September 1952, the Chief Hydrographer of Japan received a telegram from a fishing boat... (read more)
2008-01-01 01:00:00

Acoustic Technology in Historic Wreck Recovery

Remaining parts of the famous 16th century ship the Mary Rose have been recovered in Portsmouth Harbour entrance using standard offshore equipment. The use of acoustic navigation enabled both divers and ROV to work with more efficiency, precision and more conveniently. One of the more memorable broadcasts seen on British television in 1982 showed the lifting of the wreck of the Mary Rose, sunk outside Portsmouth Harbour in 1545. Although regularly monitored, the wreck site has remained largely untouched since then. In December 2002 the UK Ministry of Defence approached the Mary Rose Trust and relevant heritage agencies to inform... (read more)
2008-01-01 01:00:00

Unmanned Underwater Vehicle Showcase (UUVS 2007)

The ninth Unmanned Underwater Vehicle Showcase took place at the National Oceanography Centre (NOC), Southampton, from 26th to 27th September 2007. This conference/exhibition is one of the few (and in western Europe the only) dedicated to UUVs only.<P> Although modest in size compared with, for example, Ocean Business 2007, which was also held at the NOC, the UUVS with its 50 exhib­itors, 86 registered delegates and 350 visitors attracted many with an interest in Autonomous Underwater Vehicles (AUVs) and Remotely Oper­ated Vehicles (ROVs) and related industry. The conference delegates were classified as high quality, with good questions and discussions. Although... (read more)
2007-10-27 12:00:00
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