Maritime En Route Navigation

Applications
Title	Maritime En Route Navigation
Edited by	GMV
Level	Intermediate
Year of Publication	2011

Nowadays, ship navigation casualties and incidents can result in serious loss of life and pollution of the marine environment as modern ship can carry over 5,000 people and over 500,000 tons of petroleum. A wide variety of vessels moves around the world each day. The efficiency, safety and optimization of marine transportation are key issues.

Due to the presented reasons, GNSS is being adopted as a marine navigation tool because it provides a reliable and short cost solution, allowing interoperability across navigational areas and with great impact in safety and commercial benefits, for all maritime purposes, including leisure boats, commercial vessels, unregulated and Safety of Life at Sea (SOLAS) regulated ships.

Application Architecture

In open sea maritime navigation it is important for the ship's officer to know the vessel's accurate position, speed, and heading to ensure the vessel reaches its destination in the safest, most economical and timely manner that conditions will permit. Vessel traffic and other waterway hazards make manoeuvring more difficult, and the risk of accidents becomes greater.

The recreational boaters usually don't sail in open seas, far away from the coast. However the majority of hazards occurs precisely in areas near the shore and consequently a reliable navigation service is extremely important.

The fundamental navigational tasks necessary to support the sailor to conduct navigation safely are:

• Route monitoring,
• Collision avoidance,
• Navigation control data,
• Navigation status and data display and
• Alert management.

The GNSS applications provide the fastest and most accurate method for helmsman's to navigate, measure speed, and determine location. These features increase considerably the level of safety and the maritime navigation efficiency in order to accomplish the mentioned fundamental navigational tasks.

With augmentation systems, GNSS accuracy will meet the requirements for navigation in harbor entrances and approaches or other waters in which navigation is restricted.

Nowadays, ship's officers as well as those ashore can use enhanced information derived from GNSS in a reliably and efficient manner through the extensive electronic navigational and communication technologies and services available, such as:

• Electronic Chart Display and Information Systems (ECDIS),
• Automatic Identification System (AIS),
• Automatic Radar Plotting Aids (ARPA),
• Integrated Bridge Systems/Integrated Navigation Systems (IBS/INS),
• Vessel Traffic Services (VTS),
• Long Range Identification and Tracking (LRIT),
• Global Maritime Distress and Safety System (GMDSS) and
• Marine Electronic Highway (MEH).

These equipments and systems must be feed by an Electronic Position Fixing System (EPFS), in order to be able to perform the aimed fundamental navigational tasks.

An EPFS is a system that provides an automatic and continuous vessel's position update fitted with a suitable receiver using either a terrestrial hyperbolic radio navigation system such as LORAN-C, or GNSS.

The GNSS receivers for marine navigation are considered safety critical applications.

Application Characterization

Maritime en route navigation application

The maritime GNSS navigation is in many aspects different from the road or personal navigation. There are several typical obstacles occurring in the water, that shall be plotted by GNSS maritime navigation devices, such as rocks, sand banks, or wrecks. In addition, weather occurrences like heavy rain or dense fog, the absence of landmarks, and disorienting shorelines, implies that vessels shall have position awareness capabilities.

To support Maritime Navigation GNSS positioning needs to be integrated with navigational charts and most maritime navigation devices have been designed with usability requirements in order to include the charts embedded in the device. Navigational charts provide information about depths of water, natural features of the seabed, details of the coastline, navigational hazards, locations of natural and man-made aids to navigation, information on tides and currents and man-made structures such as harbors, buildings, and bridges. Due to safety reasons, even if the charts are embedded in the navigation device, the ship should have paper copies of the charts in order to ensure that compass navigation can be used as backup.

There are a number of features available with GNSS maritime applications. Through the GNSS maritime software, designed for marine applications, its possible to have updated maps with information, such as current patterns, prevailing winds, points of interest, fishing areas or weather information plotted onto navigational charts.

The GNSS maritime software can be operated using a GNSS receiver and a laptop, however the most common applications using this software are handheld devices or chartplotters, which are dedicated devices for maritime navigation.

Among the most prominent navigation functions available in those applications, there are:

• Ascent/descent rate
• Auto guidance
• Distance
• Electronic compass
• Elevation
• ETA (Estimated time of arrival)
• Bearing
• MOB (Man overboard)
• Speed
• Tide tab
• Time and date

Application Examples

The most notable manufacturers of maritime navigation devices are the following brands:

• Garmin owns dozens of navigation applications products, including handheld and mountable units.
• Humminbird
• Lowrance
• Magellan

Concerning the software, there are a variety of GNSS software programs available on the market. The leading brands are:

• Nobeltec,
• Digiboat, and
• Furuno

These companies provide quality GNSS software for all types of marine applications. The software programs give boaters access to powerful tools for water navigation and are easily compatible with a variety of GNSS devices.