GNSS and Hydrography

Multi-interview (1)
None of us can anymore imagine hydrographic work without satellite positioning. Improvements in performance since the first launch at the end of the70s have made it suitable for more and more applications and developments are ongoing. A GPS modernisation programme is upgrading both satellite performance and ground infrastructure, the Russian Glonass modernisation programme will upgrade performance to GPS level, Galileo test satellites GIOVE A and B are performing well and due to become available in a few years, and there is increasing augmentation system coverage. Time for Hydro International to question some experts on these developments in relation to our... (read more)
2008-01-01 01:00:00

World's First Fully Autonomous Hydrographic Survey

No Line Plan, No Boat Crew, Just Sensors
During September 2017, the world’s first autonomous hydrographic survey was performed. 'Autonomous' means not by remote control, but rather that the autonomous surface vehicle (ASV) used guidance from survey software to run pre-planned survey lines or automatically generated lines based on sonar coverage, with human interaction possible but not required. The Channel Coastal Observatory (CCO) commissioned 4D Ocean to undertake a hydrographic survey of the seabed offshore of Hurst Spit, Western Solent, using a SeaRobotics ASV 2.5. The pilot survey was supported by the Maritime & Coastguard Agency (MCA) and UK Hydrographic Office (UKHO). By Duncan Mallace, contributing editor, Hydro... (read more)
2018-02-13 11:36:29

The Arctic Field Party

It seems ironic that in the early stages of the Cold War, the United States Government sent surveyors and hydrographic engineers to the coldest reaches of the North American continent. For these men, it was truly a Cold War. From 1945 through 1953, field parties of the United States Coast and Geodetic Survey were sent to survey sea routes through the Bering, Chukchi and Beaufort Seas as well as to conduct geodetic surveys to help position Distant Early Warning system radars and help delineate the vast resources of the Alaskan Arctic. These men toiled in obscurity beneath the midnight sun... (read more)
2017-07-04 11:00:42

Bering Sea ASV Force Multiplier

Arctic Hydrographic Survey Achieves Production Gains by Utilising ASV Technology
TerraSond, a hydrographic services company based in Palmer, Alaska (USA), used a C-Worker 5 (CW5) unmanned autonomous surface vessel (ASV) in conjunction with a 105’ (32m) research vessel from June through August 2016 on a major hydrographic survey in the Bering Sea region of Alaska. The ASV served as a force-multiplier, collecting multibeam and towed sidescan data alongside the larger vessel, which surveyed adjacent lines simultaneously. The 18’ (5.5m) ASV collected 2,275 nautical line miles (4,213km) – 44% of the project total – and achieved an industry first in terms of data production rates utilising ASV technology in the Arctic.... (read more)
2016-11-22 01:57:29

Surface Imaging Capabilities on Marine Hydrographic Vessels

In a combined effort of the National Oceanic and Atmospheric Administration and private industry (Applanix and Riegl), two different but complimentary technologies were tested in the marine survey field to find a more efficient, higher-accuracy and safer alternative for traditional shoreline verification methods. This article describes the tests and the encouraging good results with this videogrammetry and laser scanning technology.<P> Vessel-based shoreline verification is a laborious, exacting and often dangerous element of nautical charting. During this process, a boat is deployed into the near-shore region to verify shoreline information extracted from aerial photogrammetry. Near-shore features such as piers, rocks, islets... (read more)
2008-01-19 12:00:00

Invited Reply

Job Satisfaction?
Working conditions in offshore surveying are sometimes pretty tough and demanding. Nevertheless, some hydrographic surveyors remain in the field until their retirement. Others leave the scene after a couple of years. The number of students attending certain educational institutes to train for this work is declining to an unacceptably minimal level. Hydro international was interested in investigating the motivation of hydrographic surveyors, their work attitude, job-satisfaction, etc. and interviewed three categories on the matter: students, surveyors and retired surveyors. Question to students What is your motivation in becoming a hydrographic surveyor, where and what do you study and what do... (read more)
2008-01-01 01:00:00

Seeking a Rift

Confused by Fracture Zones
In 1953, Hans Pettersson published Westward Ho with the Albatross, a popular account of his around-the-world scientific cruise on the Swedish sailing ship Albatross. In it he stated, “… geological evidence found in the last thirty years indicates that the Ridge is probably built up by extensive submarine volcanic action, i.e. by molten magma from deeper layers in the crust being extruded through an enormously long fissure in the bed of the Atlantic.” Although Pettersson and earlier authors certainly came close to describing the concept of a rift, it was not until the late 1950s that a rift and rift... (read more)
2014-12-15 02:06:18

Motion Sensor Performance

Direct Comparison Using 2005 Common Dataset
Integral components of a swathe bathymetry system are the motion and heading sensors. The current trend is to offer a system that combines both components in one package, either as an aided inertial sensor or as two sensors linked by component software. The quality of these inertial sensors has a direct effect on the quality of the final survey. This paper compares five leading available sensors, concluding that they produce markedly differing results. Most surveyors when purchasing or specifying a particular inertial system for a project will base their decision on information generated by the manu-facturers, which often shows all... (read more)
2008-01-01 01:00:00

Oceanology International 2010 Preview (2)

This is the continuation of the Oceanology International Preview. For companies A - L, see part 1  MacArtney Underwater Technology Group MacArtney will be introducing their newest innovation in multiplexers - the NEXUS MK E electrical multiplexer, which is designed to the same high standards as the fibre optic multiplexer range with the telemetry part of the multiplexer adapted to non-fibre optic cables. Another highlight will be the demonstration of a working active heave compensation winch, the Cormac 3 Stainless Steel winch. It will demonstrate load stability during vessel movement on the sea. MacArtney will show their Focus ROTV, camera... (read more)
2010-03-01 05:03:47

New Generation Hydrographic Databases

Enhancing data availability
The importance of data availability is increasingly being recognised, not just as an important topic for an exclusive section of the geospatial community but all over the geospatial spectrum, including the hydrographic community. If data is not available it’s no use! Traditionally, hydrographic production systems have data spread over multiple (chart) files and might be set up to include (relational) databases e.g. to store point features such as navigational aids. This has, for instance, been done for more than a decade with CARIS GIS, a widely used tool for chart production at Hydrographic Offices (HOs) and in combination with other... (read more)
2008-01-01 01:00:00
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