4.01.2012

A Very Short Note On Container Tracking Ship Tracking

By Andy Arde


Container tracking ship tracking is a system enabling the position and status of vessels at sea to be known. This activity is similar to land vehicle fleet management. It is used to achieve similar targets such as dispatching, monitoring of position and traffic assistance. The technology is very useful in managing vessel traffic in congested areas such as harbors and navigational lanes.

The system is essentially a way of reporting the locations of sea going vessels. Radio is the medium used in reporting although newer systems make use of cellular systems. GPS is used in getting a position fix

In coastal areas where line-of-sight transmission path is possible, VHF radios are commonly used for reporting of position that will be used in monitoring vessel status. The system on board ships that determine position and identification is called AIS or automatic identification system. VHF range is limited up to a distance of 25 nautical miles. AIS is mainly used for monitoring ships that are positioned near the coast.

In busy harbors, AIS is used to help in collision avoidance. It is required equipment in most large cargo ships and passenger vessels. It is possible to display AIS data on the internet using web-based mapping applications. For monitoring cargo AIS also transmits the type of cargo that is on-board the vessel.

When ships are located in the high seas too far away for VHF reception, Long Range Identification and Tracking or LRIT is used. LRIT is mandatory especially for cargo ships 300 gross tons or more. Unlike AIS which relies more on VHF, LRIT is wholly reliant on satellite communications for reporting of position.

An older system dependent on amateur radio networks is called APRS or Automatic Packet Reporting System. All APRS capable ships are transmitters and receivers of data. The data consists of vessel identity, position and other text based information. As the data circulates within the network it eventually reaches an APRS Internet Gateway. Eventually the position of the s can be displayed on computerized maps.

When position data manages to reach land based receiving stations it is relatively simple to upload the data to the internet. This allows the monitoring of ships at sea to be conducted in near-real time. Concerns have already been voiced out that freely accessible maps of tracks make ships vulnerable to piracy and terrorist attacks. Proponents of accessible maps of vessel positions counter that such vessels when approaching dangerous waters can simply turn off position reporting and vessel identification. Proponents further say that determined terrorists can simply use binoculars and pirate mother ships to spot high-value vessels plying open seas.




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