ComDev: Global Ship Tracking via Microsat

Posted by Sam Churchill on

COM DEV USA, a subsidiary of COM DEV International, today announced that it has been awarded a contract valued in excess of US$7 million to provide passive microwave equipment for a US Government space program. It follows a contract announced last month relating to the third spacecraft in the same program.

Their subsidiary company, exactEarth, offers advanced space-based Automatic Identification System (AIS-S) data services. ExactEarth is launching three AIS microsatellites, which are currently under construction in Canada and Europe.

The International Maritime Organization last year required all ships subject to the International Convention for the Safety of Life at Sea (SOLAS) to be equipped with satellite-based Long-Range Identification and Tracking (LRIT).

The LRIT unit automatically reports the ship’s identity and position to a database operated by the administration under which the vessel is flagged. This database may be viewed or queried by authorized LRIT data users, such as flag administrations, port authorities and national coast guards, at regular intervals.

In recent months, Iridium has signed agreements with four leading ASPsAbsolute Software, Collecte Localisation Satellites (CLS), Fulcrum, and Kemilinks. Together, these companies provide LRIT services to the ships flying the flags of the major maritime states. Iridium has certified LRIT devices from CLS Thorium, EMA BlueTraker and Faria WatchDog.

All ships operating in polar Sea Area (above 70 degrees) require a non-Inmarsat terminal that operates in conjunction with a low-earth orbit Communication (Iridium) Service Provider (CSP) approved by the Flag in conjunction with its appointed Application Service Provider (ASP).

Absolute has developed many of the world’s largest wide area satellite surveillance projects. The European Union Vessel Monitoring System and the South Pacific Forum Fisheries Association collectively monitor over 12,000 vessels and exchange of data between 30 countries.

AIS tracks vessel movements in real-time. Near land it works by interrogating a VHF transceiver that incorporates LORAN-C or GPS location information, with a gyrocompass or rate of turn indicators. All ocean-going vessels and commercial vessels over 65 feet are required to use AIS equipment by the International Maritime Organization. Space-based AIS provides global coverage of maritime activity, re-transmiting GPS coordinates, along with bearing and speed, every few minutes.

ExactEarth satellites will pass over Norway’s Svalbard Earth Station every 90 to 100 minutes. Located at 78 degrees north latitude, SvalSat is the world’s only established commercial station capable of downlinking on every satellite orbit. The Svalbard facility offers a high speed backhaul link via redundant fiber optic cables to transmit all data to exactEarth’s data center in Canada.

Over 70,000 ships worldwide are already equipped with Class A AIS transmitters. Until now, however, the data has been collected primarily by shore-based and ship-borne receivers where range is limited to approximately 50 nautical miles. The curvature of the Earth limits reception of the signals to approximately 50 nautical miles for terrestrial-based receivers. The key difference between Class A and Class B AIS transponders is that the Class B units transmit at a much lower power level than class A. The Class B signals are not strong enough to be reliably detected from space.

The AIS-Space data collected by exactEarth’s satellites are transmitted to a series of earth stations, and then routed by ground trunk links to exactEarth’s Data Processing Center located in Canada.

COM DEV International commissioned the University of Toronto’s Institute for Aerospace Studies Space Flight Laboratory (UTIAS/SFL) to build the experimental spacecraft. It successfully completed one year in orbit, this spring, validating Automatic Identification System technology from space. Launched on April 28, 2008, the microsat has now mapped global shipping traffic many times over and has provided the technical foundation for an operational system which is currently under construction. Initial operations of this system will commence in 2010.

“Our demonstration satellite has shown that our proprietary technology is uniquely capable of reliably detecting and de-colliding large numbers of AIS signals in the antenna field of view. The result is an ability to secure a high level of vessel detection on a global scale with the minimum number of spacecraft. This is an important performance characteristic as AIS transmissions are being sent simultaneously from literally thousands of ships that could be in the field of view of a passing satellite at any one time,” said John Keating, CEO of COM DEV.

The success of the NTS mission (Nanosatellite Tracking Ships) represents the culmination of more than five years of development. NTS, an eight kilogram nanosatellite orbiting every 90 minutes at an altitude of 630 km in a polar sun-synchronous orbit, validated COM DEV’s advanced space-based AIS detection technology as a precursor to the deployment of a constellation of AIS satellites. The constellation, when complete next year, will provide near real-time information on the identity, location and movements of marine vessels world-wide.

Here’s the real-time vessel traffic world-wide posted on, a mashup which was developed and hosted by the University of the Aegean in Greece.

Related Dailywireless stories include Shipboard AIS Gets a Satellite Swarm

Posted by Sam Churchill on Wednesday, November 11th, 2009 at 2:25 pm .

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