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

Satellite Navigation

Over 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 accuracy of a few nanoseconds time, 1cm position or 0.01-degree heading. This article explores the future development and implications of Satellite Positioning. Satellite Positioning dominates navigation at sea, in the air and on land and is now available in our cell phones and wristwatches. How it currently works was explored in the October 2006 issue of Hydro international in an article titled ‘Satellite Positioning’ (pp 35-39). But how will it work in the... (read more)
2007-01-12 12:00:00

Satellite Derived Bathymetry Migration

From Laboratories to Chart Production Routine
Much has been said about Satellite Derived Bathymetry (SDB), but with the exception of SHOM, which led to the introduction of a number of SDB charts into the French chart series, next to nothing has been implemented within the international hydrographic community. This article aims to update readers as SDB, thanks to new generation satellites and modelling, seeing the light after going through a thirty years’ tunnel. In 2014, detailed tests and analysis conducted by government hydrographers, cartographers and recognised satellite scientists operating for a number of projects initiated by the European Space Agency, the WWF and other stakeholders, were completed,... (read more)
2015-10-12 04:09:41

Precision Satellite Navigation System

Fugro Seastar AS has announced the introduction of the MarineSTAR Manoeuvring System. The system provides a highly accurate, stable position reference for ship's bridge systems such as ECDIS. Fugro Seastar claims the data to be of the highest integrity and reliability available in this industry.   In addition to position data, MarineSTAR can provide an alternative to conventional navigation aids such as gyro compass and rate of turn indicator. As well as heading, the system displays and outputs speed over the ground in both the fore and aft and athwartships directions.   The system utilises differential navigation sensors located in... (read more)
2009-06-09 12:00:00

Landsat Satellite Spots Shipwrecks

An estimated three million shipwrecks are scattered across the planet’s oceans. Most maritime mishaps occur close to shore where hazards to navigation — such as rocks, reefs, other submerged objects and vessel congestion — are abundant. It is desirable to know where they are located for many practical reasons. Streams around the wrecks create plumes that can be seen on satellite imagery in depths up to 15m, making wrecks easier to find as a recent test in Belgium showed. Belgian scientists tested this using four wrecks near Zeebrugge. Their plumes were seen by Landsat-8; the trace was followed, leading to the wrecks. The... (read more)
2016-03-15 02:53:30

Which Satellite Positioning Systems

The International Marine Contractors Association (IMCA, UK) has published new guidance on the selection of satellite positioning systems, warning that in recent years lower priority has been given to system selection than is wise. This is particularly the case when choosing a dynamic positioning (DP). The guide explains that the use of inappropriate systems has led to delays in project execution, vessel downtime and, in some circumstances, damage to assets. In the introduction to ‘Guidance on the Selection of Satellite Positioning Systems for Offshore Applications' (IMCA S 018) the association explains that the costs incurred during any of these incidents... (read more)
2011-07-08 12:00:00

Global Navigation Satellite Systems

Infrastructure Status and Developments
The concept of GNSS was first introduced by the European Space Agency (ESA), the European Commission (EC) and Eurocontrol in the early nineties. They defined requirements for a European GPS augmentation system, GNSS-1, and a full European satellite navigation system, GNSS-2, later together renamed EGNOS (European Geostationary Navigation Overlay System) and Galileo. Satellite navigation infrastructure status and developments are described here. Nowadays the term GNSS is used for the system of systems comprising GPS and GLONASS, with the later addition of Galileo. Satellite-based and ground-based augmentation systems (SBAS and GBAS) were introduced to augment GPS and GLONASS. Hydrographers were early... (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

New GPS Satellite Operational

The fourth in a series of eight modernized Global Positioning System (GPS) satellites that will deliver new capabilities to military and civilian users has been declared fully operational.   Launched from Cape Canaveral October 17, the satellite was given the all clear after an on-orbit checkout by a combined U.S. Air Force/Lockheed Martin team. Read more   The satellite joins three IIR-M satellites and 12 other operational Block IIR satellites within the current 28-spacecraft constellation. The fifth GPS IIR-M satellite is scheduled for launch on 20th December 20, 2007 from Cape Canaveral.     (read more)
2007-11-08 10:32:43

Global Navigation Satellite Systems

A Status Update
In this feature the current status and future development of four Global Navigation Satellite Systems (GNSS) are briefly presented. These four systems are the American Global Positioning System (GPS), the Russian Glonass, the European Galileo and the Chinese BeiDou Compass. All four systems offer, or will offer, civil navigation services (publicly open), as well as restricted access navigation services, which means for GPS, Glonass and most likely for Compass as well, military services. The European Galileo system will offer so-called Publicly Regulated Services (PRS) for use by the government. The basic principle of satellite navigation – referred to as standalone... (read more)
2011-03-16 12:04:30
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