VII International forum
“Marine Industry of Russia”
Hotel complex
«President-Hotel»
Department of affairs of the President of the Russian Federation

Moscow, 24, B.Yakimanka Str
24-25 May 2017
 
Forum bulletin


Navigation Systems – Brief Overview

Some time seamen used celestial navigation relying on visual acuity only. As the years went by, the store of navigation instruments was widened with a compass, log-line, lead line, surveying compass and chronometer. Then the time came for an astrolabe, quadrant and later for a sextant – a tool for measuring angular coordinates of celestial objects. The last was invented in 1730, and thanks to multiple precision of measurements, it significantly facilitated the life of seamen.

Inertial Navigation Systems

In the early 20th century, first gyrocompasses were designed which by gyrorotor ability to maintain given direction. At present, manual and automatic ship steering systems use gyrocompasses as a supporting navigator. As a rule, the marine gyrocompass is very heavy, and its rotor weights over 25 kg.

Indications of a gyrocompass and linear accelerometer sensors (accelerometers) are used for calculating position of a vessel. Data of satellite navigation system, radio navigation, magnetic compass, and odometer (instrument used to register travel) help to compensate related errors.

Radio Navigation Systems

In the middle of the 20th century, radio navigation systems were designed, the first was LORAN-A (LORAN — Long Range Navigation), USA. Shore radio stations sent signals at stated intervals, seamen received them and determined the ship location basing on the time difference between the receipt of signals from two or more stations.

Today, this method is still in use. Among hyperbolic navigation systems, the most commonly used systems are LORAN-C pulse-phase time-difference system and OMEGA which works at lower frequencies (and, consequently, ensures bigger reach). The main application field is sailing in the coastal waters.

Satellite Navigation Systems

In the middle of the 20th century, radio navigation systems were designed, and later satellite ones. At first, these were low-orbit Transit and Tsikada (Цикада), then the time came for American GPS (Global Positioning System) also known as NAVSTAR, and Russian GLONASS (Global Satellite Navigation System).

Accuracy standards for navigation are specified by Resolution of IMO A529, 1983, and A815, 1995. Both GPS and GLONASS are equally accurate in determining location. For civil users, the accuracy of the system is 15 meters with probability 95%. Obtained values are enough for the purposes of common navigation.

Several years ago countries of European Union started deployment of their own navigation system – Galileo. It is expected to operate in the restricted and free access mode with 10 meter accuracy.

Control-Correcting Stations

Control-correcting station (CCS) networks are deployed to extend precision of positioning and check data of satellite navigation systems. Within the coverage (about 300 km), the accuracy from 1 to 5 meters is ensured with probability 95%. CCS consists of a reference station, integral control station, radio beacon, remote station and control point placed aboard. The reference station receives signals from GNSS satellites and basing on exact coordinates of its receiving antennas calculates differential corrections for navigational parameters. CCS radio beacon transmits calculated corrections to ships. Thus, it is possible to determine location within the accuracy of some meters.

It is natural that CCS network covers only a part of the globe. These systems are used close by ports with the heaviest traffic as well as where the works with hazardous cargoes and petroleum products are carried out.

In the early 1990’s, most leading marine states ensured total CCS network coverage of coastal waters.

Situation in Russia

Owing to the regulations of the government of the Russian Federation of 2005 and 2008, the domestic satellite navigation system GLONASS is used more extensively in Russia. As a whole, such systems were deployed in all principal navigation regions of Russia already in 80’s.
The major obstacle to the country-wide implementation of the system is insufficient usage of electronic navigation charts.

Nowadays, the national program of placing GLONASS/NAVSTAR differentiated subsystems is being implemented; this program is based on marine radio beacons over the seacoast (CCS). The coverage of such subsystems is about 250 km.

As early as in 1999, the station in the Gulf of Finland was put into operation. Since then the networks at the coast of the Black, Azov and Caspian sea were built as well as at some sectors of inland waterways. In 2006, CCS in Peter the Great Bay and adjacent part of the Sea of Japan was built. In addition Russian CCS can work both with GPS and GLONASS.

 
 
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