Satellite Positioning

Within the last twenty years Global Positioning System (GPS) receivers have revolutionised navigation. Integrated devices are capable of providing time, position, height, direction, heave and attitude to accuracies of a few nanoseconds time, 1cm position or 0.01 degree heading. All potentially displayed on a digital chart background with radar and auto-identification system overlays. In this first of two articles we look at current Satellite Positioning systems, how they work and how we can make them better. In a second article, to appear next month, we explore the future development of Satellite Positioning and the implications for navigation. How does Satellite... (read more)
2008-01-01 01:00:00

Underwater Positioning

Centimetric Accuracy Underwater-GPS
By Camille Béchaz, ACSA and Fran­­çois Boucquaert, Fugro-Topnav, France Fugro evaluated the accuracy of the GPS Intelligent Buoy (GIB-Lite) system for its possible use in shallow-water offshore underwater positioning applications. The trials proved that system accuracy could be brought up to centimetre level, the distance between two simultaneously tracked acoustic pingers having a standard deviation of 8cm. Additional works next to an offshore production platform are often required to increase oil recovery from an existing reservoir or to maintain its production rate over a longer period of time. The seabed near such a production platform typically shows pipelines, electric cables,... (read more)
2008-01-01 01:00:00

Deepsea Positioning Accuracy

First NEMO Tower for Astrophysical Research
The Italian Istituto Nazionale di Fisica Nucleare (INFN) is developing a large underwater apparatus to investigate new frontiers in astrophysical research. The NEutrino Mediterranean Observatory, NEMO, consists of a 3D-array of optical sensors capable of detecting the primary source of extremely high-energy neutrinos. This article covers underwater positioning techniques: system architecture, technical, advanced and data processing aspects, and preliminary data analysis. The first prototype, NEMO Phase 1, was deployed in December 2006 off the coast of Catania. A set of synchronous acoustic beacons was installed in the sea at a depth of 2,000m to position a large number of optical... (read more)
2007-05-31 12:00:00

Subsea Positioning Transponders Order

Unique Systems (USA) has taken delivery of a major consignment of Compatt 5 subsea positioning transponders from Sonardyne. The order complements Unique's existing worldwide inventory of Sonardyne acoustic equipment which includes RovNav 5 Long BaseLine transceivers and Ranger Ultra-Short BaseLine systems.     Unique Systems is part of the Unique Group based in Sharjah (UAE), which is a major distributor and rental company for advanced marine and diving equipment. The Compatt 5 equipment will be made available to rent from their additional US office in Houston which opened a year ago to support clients and offshore projects throughout the Gulf... (read more)
2009-07-03 11:21:09

Indian Positioning Contracts

Four of India's leading DP vessel operators in Mumbai have each commissioned Veripos to provide medium to long-term high-precision GNSS positioning products and services for their respective domestic and international offshore operations.     The companies include Greatship India who have commissioned Veripos' Standard positioning service and LID3-G1 hardware on DP vessels, Greatship Amrita, Greatship Anjali, Greatship Dhriti, Greatship Disha, and Greatship Diya while a further four vessels are to be supplied with similar facilities later this year.  The company, which has recently had vessels operational in the Middle East, Mexico and South Africa as well as its domestic market in India, is currently engaged in... (read more)
2009-06-23 03:51:21

Further Petrobras Positioning Contract

Veripos, UK, has been awarded a long-term contract by Petrobras, Brazil, for provision of positioning services in support of the Brazilian state-owned company‚Äôs BGL-1 pipeline installation barge operations.     Under the two-year contract, which includes an option for a further two years, Veripos will provide the 122-metre dynamically-positioned barge with continuous choice of its all-purpose Standard, Ultra and Differential Glonass positioning services supported by LD2-G2 mobile receiver equipment and Verify QC software for real-time position and quality control information.   The contract is the second to have recently been awarded to Veripos by Petrobras following an agreement last year... (read more)
2011-04-28 11:51:06

Survey and Positioning Contract

Aberdeen-based DOF Subsea UK has been awarded a contract worth around GBP2 million by Technip to provide survey and positioning services in BP-operated Block 31, offshore Angola. DOF Subsea will be supplying the services onboard the Skandi Bergen (supplied by DOF Subsea under a separate contract) and on board Technip's lay vessel the Deep Blue. It is anticipated that the project will commence in Quarter 3 2010 and will last for approximately 119 days. DOF Subsea provides subsea construction and engineering, IRM, ROV and survey support services to the world's major subsea markets. The company employs over 1,200 highly qualified... (read more)
2010-02-17 04:44:56

Community-sourced Positioning Project

The TeamSurv consortium offers sailors and powered boaters the opportunity to join a community that collects and shares depth information recorded by vessels' existing depth sounder equipment. Depth data, along with the vessel's position, are automatically logged and stored in real time, either by a software utility running on a Windows PC or using a dedicated hardware logging device. At the end of the voyage, the logged data is uploaded to the TeamSurv website. Submitted data are combined and processed, using unique algorithms, by TeamSurv and are corrected for actual or predicted water levels and other factors so as to... (read more)
2010-03-01 11:09:49

Dynamic Positioning Conference Programme

The Dynamic Positioning Committee of the Marine Technology Society has issued an Advance Programme for the 2010 Dynamic Positioning Conference. The Annual Conference will be held at the Westchase Hilton, Houston 12th and 13th October 2010. The Conference traditionally places a strong emphasis on new technology and this year is no exception with sessions on DP in The Arctic and New Applications, as well as a full session on Quality Assurance. As in the past, there will also be sessions on Design, Sensors, Thrusters and Operations. Expanded exhibit space will allow a larger number of vendors to display their products... (read more)
2011-02-24 09:10:54

LBL Underwater Positioning

Long baseline (LBL) positioning has many applications both commercially and in research, from surveying a ship hull to positioning offshore platforms in deeper waters. The technique consistently provides accuracies in the order of decimetres over large areas, independent of depth. Recent advances include the integration with other acoustic techniques or with inertial navigation systems for greater levels of accuracy. Since navigation by GPS isbased on electromagnetic signals that cannot penetrate water, subsea positioning requires a different approach. As sounds waves travel through the sea they alternately compress and decompress the water molecules; these compressions/decompressions are detected as changes in pressure.... (read more)
2008-01-19 12:00:00
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