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

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

Veripos Americas Positioning Contracts

Veripos' Houston-based Americas Region has been awarded major offshore positioning contracts by DOF Subsea, LSP, Tidewater and WesternGeco for vessels operating in Brazilian, Mexican and US waters. The contracts also cover supply of proprietary integrated demodulator and GNSS receivers and associated software modules to ensure seamless high-precision sub-metre positioning for survey, construction support, seismic and general offshore operations.   Facilities being provided to LSP for its well-testing vessel, Aires Swan, operating in Mexican waters on long-term contract to PEMEX include Veripos' dual-beam Standard and Standard HF augmentation data services together with LD2 and LHD2 integrated demodulator and GNSS receivers. Meanwhile,... (read more)
2008-08-05 01:40:52

European Precise Positioning

Ground-based Regional GNSS Augmentation
Global Navigation Satellite Systems (GNSS) like GPS, GLONASS and, soon, Galileo are used for many positioning and navigation applications. But existing GNSS accuracy and reliability do not satisfy all clients. Ground-based augmentation systems provide GNSS observation data and real-time corrections for high-precision positioning and navigation. EUPOS is an initiative to build and run such systems with uniform standards and full-scale accuracy in fifteen Central and Eastern European countries. The European Position Determination System (EUPOS) is both an international initiative and a project to establish a uniform Differential GNSS basis infrastructure in Central and Eastern Europe (CEE). Uniform ground-based multifunctional DGNSS... (read more)
2008-01-01 01:00:00

Brazilian Offshore Positioning Contracts

Veripos has been awarded a series of contracts in Brazil under which it is to provide high-precision GNSS positioning products and services to leading offshore operators, DOF Subsea, NorSkan Offshore and Companhia Brasileira de Offshore (CBO).     The DOF Subsea contract includes the provision of Veripos Ultra dual-beam precise-point positioning (PPP) service supported by two LD2-G2 integrated mobile demodulators and proprietary Verify QC processing software aboard the ROV support vessel, Skandi Chieftan.  Similar facilities have already been operational for some time aboard the company's other ROV vessels, Skandi Fluminense and Skandi Salvador.   Meanwhile, DOF Subsea's associate Brazilian concern, NorSkan Offshore, is to... (read more)
2009-08-19 03:45:48

NPCC DGPS Positioning Contract

The National Petroleum Construction Company (NPCC) of Abu Dhabi, UAE has awarded C&C Technologies (Asia Pacific) Pte Ltd, a long-term contract for their C-Nav Globally Corrected GPS (GcGPS) positioning services. This is the fifth consecutive year that C & C Technologies, with its C-Nav positioning service, has been awarded this prestigious contract.   The contract also marked the beginning of a new partnership, as this will be the first collaborative effort with the recently appointed sub-distributor, Technical Equipment Service ME (TESME) in Abu Dhabi.   NPCC will utilise the wide range of positioning services provided by C-Nav to deliver high... (read more)
2008-03-05 10:46:10

Apex GNSS Positioning Service

Veripos has extended its range of services with the introduction of Apex, a new high-accuracy positioning solution. Complementing the company's existing Ultra service, Apex similarly uses precise point positioning (PPP) methods for correction and/or modelling of GNSS error sources. Each service operates independently, providing continuous decimetre-level accuracies. For delivery of the Apex service Veripos operates its own orbit and clock determination system (OCDS) which derives real-time corrections for all GPS constellation satellites using proprietary algorithms. Data is taken from the company's global network of more than 80 reference stations, with multiple and redundant OCDS systems running in parallel from two... (read more)
2010-04-06 11:04:46

Indonesian Positioning Contract

Veripos has been awarded a two-year contract by hydrographic survey and subsea specialists PT Pageo Indonesia of Jakarta for provision of high-precision Differential GPS positioning services in support of major site survey and rig-positioning operations being carried out in the Mahakam Delta, Kalimantan on behalf of Total E&P Indonesie, a subsidiary of the Total Group of companies.   The services, which include supply of Veripos' latest LD3 integrated mobile GPS receiver and demodulators for calculating positions and output of data, are being used in support of jackup, semi-submersible and swamp drilling barge operations as well as shallow water survey vessels... (read more)
2008-02-04 03:25:53

Workshop on Underwater Positioning

The Hydrographic Society organised a workshop on underwater positioning and navigation on Wednesday 10th December 2008. On board of the tug RenĂ© Siegfried, three presentations were held, touching various aspects of the matter.   Hans-Willem de Leeuw (sales engineer, IXSEA Benelux) explained the principle of the fibre optic gyroscope and introduced various applications of this technique in the IXSEA product range. Especially in the offshore, there is a demand for precise underwater navigation and the combination of the fibre-optic gyroscopes with GPS or DVL make the positioning more accurate, even after hours.   Neil MacDonald (technical manager, Applied Acoustics) went... (read more)
2008-12-12 10:30:25

Deepwater Positioning Buoys Shipment

Falmouth Scientific has shipped 30 deepwater positioning buoys worth almost half-a-million US dollars to the Integrated Ocean Drilling Program (IODP). These beacons will be employed by IODP's drilling vessel for deepwater (6000-meter) positioning. FSI's instruments will be used to accurately position IODP's drilling ships in order to extract cores of the Earth's crust at the bottom of the ocean.   The mission of the IODP is to explore Earth's history and structure recorded in seafloor sediments and rocks, and to monitor sub-seafloor environments. Their efforts are part of a global team from the US, Japan, China, Korea and Europe.  ... (read more)
2008-08-14 12:14:15
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