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From Ship to Shore to Satellites

By Mary Jo Wagner
It used to be that the Marine Communications & Traffic Services (MCTS) branch of the Canadian Coast Guard was primarily interested in any target less than 50 miles from Canada’s shores. But then September 11th came, and as it’s happened to so many government agencies, the MCTS’ service responsibility changed. Now the MCTS needs to receive advance reports from vessels over a thousand miles off the coasts of Canada.

This increase in the branch’s “line of sight” requirements has prompted the MCTS to augment its existing conventional vessel-monitoring methods including shore-based radar and vessel call-ins with new technological approaches such as automatic identification systems (AIS) and, most recently, it began to experiment with RADARSAT-1 satellite information. Both technologies could help the MCTS personnel, along with government colleagues in other agencies such as the Department of National Defence, to keep an eye on what’s beyond the horizon.
Safety first
The MCTS branch operates five centres that control a total of 32 remote radio and eight radar sites along the West Coast of Canada. It is one of the seven marine programs within the Canadian Coast Guard. Its primary mission is to save lives at sea and to provide accurate vessel traffic and safety information to transiting vessels. With a distributed network of stations, radar receivers and radio frequencies, MCTS personnel continuously monitor international distress and calling frequencies, coordinate rescue efforts, disseminate weather and safety information and track the movements of commercial, government, fishing and other types of vessels navigating within traffic sector boundaries.
Tracking targets
Any vessel planning to enter Canadian or US waters must send a 24-hour-advance report and a 96-hour-advance report, which includes its position, course and speed. Although the 24-hour report has been in effect for a number of years, the 96-hour-report came into effect as a result of Sept. 11th.

To monitor this vessel traffic, the MCTS uses a host of surveillance methods. Inmarsat-C satellite communication is used to send and receive the ship reports, which are transmitted to the MCTS’s marine information center located in Vancouver, BC. Shore- based radar picks up shipboard radar signals within 50 miles of shore and tracks their location, course and speed to the marine information center. In areas where no radar is available the MCTS uses “dead reckoning” - the ship’s captain calls in his position, course and speed. And recently, the MCTS began test trials of AIS, a mandatory initiative that requires all newly built vessels over 300 tons to have a shipboard transponder, which will use internationally designated VHF frequencies to transmit their positions. AIS is being phased in over the next five years, starting with all cruise ships and tankers, which must be fitted with AIS in 2003. There is a very good chance that this phase-in period will be fast tracked as a result of Sept. 11th.

Tracking all the ship traffic is MCTS’s proprietary vessel monitoring system called VTOSS (Vessel Traffic Operations Support System). A computer system similar to an air traffic control system, VTOSS plots and continuously tracks all reported vessels within 800 miles of Canadian territory. Each time a vessel’s location, course and speed are reported in, a color-coded icon resembling a tiny lollipop appears on the VTOSS screen. The color indicates the information source (Radar, Inmarsat, AIS, etc) and the “lollipop stick” indicates the course the vessel is heading. Clicking on any icon will provide personnel with the ship’s attributes such as its name, its course and its speed. The icons then move across the display as VTOSS continues to track the vessel.

Although the MCTS’s surveillance methods and tools provide staff with an effective system to monitor vessels, the system is vulnerable to two overriding issues. One is that to some extent vessel monitoring is based on an honor system - MCTS staff trusts that ship captains will report in and provide accurate information. And second, legislation dictates that vessels less than 20 meters are not required to report in. It is in this arena where information derived from RADARSAT-1 satellite imagery could be of benefit.

From shore-based to satellite-based radar
To try to safeguard against unknown vessels, the MCTS began a two-week trial in April in conjunction with RADARSAT International (RSI) to test the strength of RADARSAT as an operational surveillance tool.

At the beginning of the project, ScanSAR Narrow imagery over the West Coast EEZ was acquired twice daily - once in the morning and once in the evening - and downlinked to the Gatineau, Canada ground station for processing and interpretation. After the initial results were in, the decision was made to switch to Single Beam, W2 and W3 because critical information such as speed and heading information were more easily derived from this beam mode than from ScanSar Narrow. RSI personnel process the imagery to identify possible targets and then compile text-based ship reports complete with the date and time each image was acquired, the latitude and longitude of the scene, the wind speed and sea state, the presence of any environmental risks such as oil slicks and the location, course direction and speed of each target identified. The report is sent to an FTP site for VTOSS to automatically access and to download.

Once MCTS personnel retrieve the RADARSAT-derived ship report, they ingest that data directly into VTOSS and all vessel positions are automatically plotted on the VTOSS display, complete with a color-code to indicate its RADARSAT-derived information. MCTS staff can then view the newly plotted vessels and verify who they are and their positions through other information sources such as call-ins or shore-based radar. If any vessel doesn’t correspond to any reported data or any other vessel location, then it is coded as suspect. As the DND has a direct link to MCTS’s VTOSS, personnel can then note the number of suspect vessels and dispatch aircraft to possibly investigate.

Vtoss4- April 11: RADARSAT-derived ship reports are ingested directly into VTOSS and all vessel positions and they’re course heading are automatically plotted on the VTOSS display. Those icons in red indicate they’re RADARSAT-derived information

Vtoss6-April 11: VTOSS plots and continuously tracks all reported vessels within 800 miles of Canadian territory. MCTS personnel can then use the information to verify and to monitor vessel activity to promote efficient movement of marine traffic. The trajectory lines shown here, for example, project where vessels could collide if they continue on their same course. Staff could suggest routes to avoid any accidents.

Imagery is also being acquired over eastern Canada to provide ship reports via the Internet to the MCTS’s colleagues on the East Coast.

To date, the RADARSAT-derived ship reports have proven useful to the MCTS, broadening the agency’s view of ship traffic and detecting vessels that might have otherwise gone undetected. By integrating RADARSAT data automatically into VTOSS, and ultimately into the DND’s operational system, MCTS personnel have a layer of information previously unavailable, providing a valuable complement to their existing surveillance tools. In particular, RADARSAT-1 data will supplement AIS data to identify vessels not equipped with AIS or those that are not reporting because AIS is inoperative or deliberately shutdown to elude detection.

Provided the MCTS can receive ship reports on a consistent basis and the accuracy of the target’s speed and direction can improve, RADARSAT-1 could be another valuable monitoring tool to help the MCTS fulfill its mission.
This article was first published in RADARSAT International’s e-Reflections Newsletter Issue 4/Vol 2 and has been reprinted with the permission of RADARSAT International - Copyright (c) 2002, RADARSAT International.

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