Operational Use of Ship Detection to Combat Illegal. Fishing in the Southern Indian Ocean. Marcel Losekoot, Philippe Schwab. Collecte Localisation Satellites ...
Operational Use of Ship Detection to Combat Illegal Fishing in the Southern Indian Ocean Marcel Losekoot, Philippe Schwab Collecte Localisation Satellites (CLS) 8-10 rue Hermes, Parc Technologique du Canal, 31520 Ramonville, France
Abstract -The Kerguelen plateau in the Southern Indian Ocean is home to the highly sought-after Patagonian Toothfish, Dissostichus eleginoides, or Chilean Sea Bass. The efficient enforcement of fishing quotas and the repression of illegal fishing activities within the French and Australian exclusive economic zones represents a significant challenge to maritime authorities due to the size and remoteness of the area. Synthetic Aperture Radar (SAR) satellites are used to detect illegal vessels, thereby allowing patrol vessels to intercept them in a much more efficient and timely manner. The SENTRY transportable groundstation from IOSAT Inc. of Halifax was upgraded and deployed on Kerguelen Island where it autonomously acquires, processes and analyses images from the Radarsat-1 and Envisat satellites. Four times per day the station automatically produces ship reports less than two hours after each pass. The ship reports are combined with Argos positions from legal vessels in order to locate illegal vessels and direct patrol vessels. The station has been in successful operation for over a year and has demonstrably contributed to the repression of illegal fishing activities
I. INTRODUCTION Kerguelen is a French archipelago situated in the Southern Indian Ocean, over 4000 km from South Africa or Australia and only 2000 km from Antarctica. The islands are the exposed tip of a volcanically created underwater plateau that creates favourable conditions for catching the Patagonian Toothfish. This large deep-water fish can live for 50 years, reach a length of 2 m and weigh 60 kilos. With a spawning age of about 10 years it is difficult to determine long-term sustainability of the population in the face of current levels of fishing.
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The world annual authorized catch for the species is set at 30,000 tons of which 6400 tons are allocated to the Kerguelen area and most of the rest to Chili. In addition to the seven long-line trawlers licensed by France to operate within its EEZ, vessels from around the world come here to illegally haul in an estimated 30,000 tons of the precious cargo and then sell it for 5 to 10 USD per kilo, making this fish one of the world’s most lucrative illicit commodities. The fishing gear of illegal vessels also hook and drown an estimated 60,000 seabirds every year. The high potential rewards incite highly organized operations involving ruthless pirate vessels that can only be deterred through the coordinated efforts of armed Navy vessels from French, Australian and South African authorities. On several occasions over recent years, illegal fishing vessels have been detected by patrol vessels and dramatic chases across thousands of kilometers including ice-bound waters have ensued before the vessels were, in some cases, successfully apprehended. Typically, impounded vessels are not reclaimed by their owners and eventually sunk offshore. Effectively patrolling the seas around Kerguelen presents significant logistical problems to the authorities. Heavy seas make detecting and following a suspect vessel a significant challenge. Despite regular patrols by both French and Australian vessels, the sheer size of the area to be covered - 3 million square kilometers - makes it impossible to obtain a complete and correct picture of the number of vessels and their locations. Helicopter survey missions from the patrol vessels can extend the area covered, but not all patrol vessels
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are suitably equipped and heavy weather seriously limits their use.
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Figure 1. Typical unauthorized fishing vessels a) The "Mar Del Sur II", b) The "Varsia".
In the summer of 2000 the French government decided to evaluate the contribution that satellite radar could make to improving the effectiveness of enforcement activities and simultaneously protect the economic activity of the French fishing companies based on La Réunion Island (near Madagascar) whose vessels trawl the EEZ surrounding the French islands of Kerguelen, Crozet and Amsterdam.
II. A VESSEL MONITORING SYSTEM (VMS)
A preliminary step had already been made in the late 1990’s with the implementation of a vessel monitoring center based on the Argos system, allowing the authorities on La Réunion to locate all licensed fishing vessels and other French vessels present in the area, such as research and supply vessels.
Figure 2. The Argos fishing vessel transmitter and Vessel Monitoring System provide authorities with the positions of legal fishing vessels.
A pilot project was conducted over the latter part of 2000 in which Radarsat International (RSI) provided the French authorities with ship detection reports. Radarsat-1 was operated over the Kerguelen and Crozet areas, the data was recorded and played back over Gatineau, then processed and analysed by RSI operators. A ship report for the acquisition was generated and emailed to the French authorities, generally within 7 hours. On La Réunion, the report was automatically integrated into the VMS to simultaneously display the
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positions of the vessels detected by RSI with the positions of known vessels, interpolated to the time of acquisition. The result was a map that had never been seen before and could not be obtained in any other way. For the first time, snapshot views of all vessels present within the imaged swath could be visualized, allowing the vessels to be located and counted, providing essential information for the authorities. A number of surface operations were organized to coincide with satellite passes, leading to the arrest in November of 2000 of a notorious illegal fishing vessel, the “Monte Confurco”. Bolstered by the success of the pilot project, a new project was born whose objective was to create an operational system that would give the authorities the information they needed to continuously and effectively force the illegal fishing vessels out of the French EEZs. III. SHIP DETECTION BY RADAR SATELLITE
The reasons why Synthetic Aperture Radar (SAR) satellites are so effective for monitoring illegal fishing in the Kerguelen area can be summarized as follows: 1. The EEZ can be monitored by day or by night, despite almost continuous cloud cover. 2. Fresh data for part of the zone is available on a twice daily basis. 3. The surface area covered per day far exceeds that covered with traditional patrol methods. 4. All vessels are detected, including non-cooperative unknown vessels. The main operational limitations of currently available SAR satellites are the following: 1. Very few satellites provide operational SAR data, thereby limiting the number of passes available per day and keeping data costs high. 2. Swath widths with the required resolution allow only part of the EEZ to be covered, approximately 10% per day in the case of Kerguelen. 3. Vessels cannot be identified or tracked using the SAR data alone. The SAR satellite data is processed to generate position reports that are used in two distinct ways: 1. at EEZ level, in order to determine vessels density, distribution and general movements, and 2. at individual target level where those targets that are confirmed yet unidentified can be intercepted. Both uses require that known legal vessels are automatically located and accounted for, allowing illegal vessels to be reliably counted or intercepted. The VMS allows for this by automatically integrating ship detection reports and displaying both ship report targets and known vessels on the same map. The operator is then able to classify targets as known or unknown and act accordingly.
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The operating principle of a system combining VMS and satellite radar is shown in Figure 4 below. Kerguelen
Satellite swath
RADARSAT-1 ENVISAT Target position reports
COSRU Argos vessel positions
CLS
NOAA
•
The climate is sub-Antarctic (0°C to 15°C) with almost continuous high winds, imposing the use of a radome. • Local resources are limited to general supplies, tools and non-specialist support personnel. • All specialist items, tools and consumables must be shipped specifically. • Communications are limited to a 64 kbps VSAT link and satellite telephones.
Surface Situation report
NAVY
Figure 3. Operating principle of the combined VMS and Ship Detection system.
The following additional operational requirements were identified: 1. The area covered on a daily basis must be maximized and the revisit time must be minimized, both through the use of optimal satellite modes and through the use of several satellites. 2. The delay between the acquisition and the generation of the ship report must be minimized in order to support surface operations. The objective is two hours with a maximum of four hours.
Figure 4. General view of the Kerguelen base, “Port aux Français” with the RV “Marion Dufresne II” at anchor.
In January 2003 the decision was made by the French government to finance such a system with an imperative to be operational by the end of the year. V. THE SENTRY STATION
IV. KERGUELEN ISLAND In 2002 a feasibility study was performed which determined that the only way to meet operational requirements and remain within budget was as follows: 1. A direct reception station must be located on one of the French islands within the area of interest. 2. The station must automatically receive and process the satellite data. The level 1 images must be analysed automatically and ship reports generated within the station, as the level 1 images cannot be transferred to the operations center, due to their size. 3. The ship detection products created in the station must allow the remote operator to visually classify potential targets in order to separate false targets from confirmed targets. 4. The positions of confirmed targets must be automatically integrated with VMS data to easily and rapidly separate known vessels from unknown vessels. 5. The station must be operated and maintained remotely with a minimum of on-site intervention. The study identified Kerguelen Island as the only location with the necessary infrastructure for installing and operating such a station. Although the island has the general infrastructure and facilities of a sub-Antarctic research base, installing and operating a Radarsat station there presented a number of unique difficulties: • Transport to Kerguelen is limited to one supply vessel that makes four journeys per year. High seas make winter access impossible because the supply vessel cannot dock at Kerguelen and there is no airport.
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A direct reception station suitable for an operational application such as this must satisfy very specific requirements: 1. The station must be self contained, transportable and deployable on Kerguelen. 2. The station must have a high degree of autonomy, reliability, redundancy and low maintenance. 3. The station must have high performance reception and processing elements, including automatic ship detection performed within the station in less than two hours from the pass. 4. The ship detection products must be transferable over a low speed network connection. 5. The station must feature full remote operation including remote configuration, software upgrades and diagnostic logs. Just such a station had been developed over a period of 2 years by IOSAT Inc, a subsidiary of Satlantic Inc of Halifax, Canada. The SENTRY fulfilled exactly this role and it had all the right ingredients to become the Kerguelen station. Its ship detection performance had been proven in test campaigns for the government of Canada.
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The SENTRY station consists of a Scientific Atlanta transportable antenna subsystem with a 5.4m reflector, similar to those of the Eagle Vision series. A custom 20 foot container houses all power, air conditioning, tracking, reception, processing and communications equipment.
VII. THE INSTALLATION Following the upgrade and validation process during the summer of 2003, the station was shipped to Kerguelen, arriving there in December 2003. In parallel with these activities, a radome was constructed, validated with the station during tests in the summer and shipped to Kerguelen. Work on the Kerguelen radome base and all specific station infrastructure started mid 2003 and was completed before the arrival of the station. The station was installed over the Christmas and New Year 2004 period, with first data acquired in January 2004. c
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Figure 5. The Sentry, a self-contained, transportable Radarsat groundstation.
The station is capable of operating as a Certified Radarsat Network Station, automatically scheduling passes, performing pass tracking, data acquisition, data processing, ship detection and reporting of the results. The data is automatically forwarded to the end user by email without human intervention. Routine housekeeping tasks are all performed remotely via the network. VI. THE UPGRADE The SENTRY was transported from the Halifax quayside to Toulouse France in the spring of 2003 for upgrading. The upgrade consisted of replacing and duplicating the reception and demodulation equipment and duplicating the data handling computer systems including the Radarsat processor. The Radarsat ship detection is performed by the Ocean Monitoring Workstation (OMW) from Satlantic Inc. of Halifax. The OMW that was integrated in Sentry continuously and autonomously detects potential targets and extracts ship detection products from the level 1 images. The OMW was modified to provide an enhanced output product suitable for remote operator verification. The ship detection products consist of a correlated report listing detected targets, a subsampled preview of the scene and full resolution ‘chips’ of the image immediately surrounding each potential target. The SENTRY was also upgraded to receive a dual Envisat acquisition and processing system, supplied by Kongsberg Spacetec AS of Tromsø, in Norway. These servers are capable of automatically acquiring and processing Envisat ASAR data, automatically performing ship detection and generating ship detection products (position report, scene preview and image chips) with the same format as OMW. The station was also fitted with a power conversion and protection stage, allowing it to be run reliably off Kerguelen’s European standard diesel alternator.
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Figure 6. a) the SENTRY deployed, b) ‘preview’ scene of Kerguelen, c) target image chip.
VIII. OPERATIONS Satellite passes over Kerguelen are scheduled via RSI for Radarsat and via ESA for Envisat. The station automatically schedules passes and performs all acquisition, reception and processing functions for both Radarsat and Envisat, including the automatic ship detection within two hours of the pass. The ship detection products for a complete pass of 10 scenes are transferred to the operations center in La Réunion within 10 minutes. The raw data is automatically archived by the station and then deleted. The ship detection products are visually classified by trained operators in La Réunion to eliminate false echoes and retain only confirmed targets. These are then compared with VMS positions in order to eliminate known vessels and retain only unknown and therefore presumed illegal vessels. The surface situation is reported to the Navy for further intervention. In the event that the station is unavailable for a significant period of time due to maintenance or repairs, a backup mode is used wherein Radarsat-1 records acquired data on-board and replays the data over Gatineau. The data is processed and ship detection products are generated using OMW to generate the exact same products as the station, allowing the end user to retrieve and use the data in exactly the same way as with the station. The backup mode is limited to fewer scenes (50%) and longer delays (up to 24 hours) but most importantly it allows the end user to accept the possibility of prolonged periods of unavailability due to the remoteness of the station.
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IX. RESULTS
ACKNOWLEDGMENT th
The station has been operating continuously since the 9 of January 2004, a total of 446 days to date. The operational statistics have been measured over a period of one year from the 1st of March 2004 to 2005. Table 1. Performance summary of SENTRY station operations, measured over one year. Performance parameter
Radarsat
Envisat
Days of operation per year
315
365
Passes scheduled
937
980
Passes acquired
881
913
Scenes processed
8000
9000
Remarks 50 days of Radarsat-1 eclipse Approx. 2-3 passes per day 94% and 93% success rate Approx. 25 scenes per day
CLS acknowledge the invaluable support of Bob Allan of Nova-Consult throughout all phases of the project. Our thanks go to all from Satlantic and elsewhere who contributed to creating the SENTRY and OMW; to RSI whose generosity ensured a successful pilot project; to Michel Starozinski, CNES and TAAF for taking care of the infrastructure in Toulouse and Kerguelen; to Spot Image and Spacetec for the Envisat upgrade; to SMP France and Polycontact Industrie for really fast work; and finally to Pierre Engel of Mea Intuis for making it all seem feasible. BIBLIOGRAPHY
The effectiveness of the system in deterring illegal fishing activities has been confirmed (albeit off the record) both by the French authorities and by the licensed fishing companies: • The timely provision of position information contributed to the arrest in June 2004 by the French authorities of the FV “Apache” near Kerguelen. • The regular position reports have allowed patrol vessels to ‘appear’ near illegal vessels whenever such vessels approach the EEZ, clearly demonstrating the authorities’ ability to monitor movements and react. • There has been a sharp decrease in the number of illegal vessels present in the area around Kerguelen, presumably due to their perception that the chances of being detected and apprehended have increased beyond the point where fishing there is worth their while. These vessels are presumably now fishing elsewhere.
R. T. Allan, R. B. Olsen, M. R. Lewis, T. L. Duffield, “Transportable Satellite Imaging Terminal for RADARSAT” In Proceedings of the 1st International Symposium The Expansion of the Remote Sensing Market, Paris, France, 7Mar-95. P.W. Vachon, R. B. Olsen, “RADARSAT SAR mode selection for marine applications”, In Backscatter, Newsletter of The Atlantic Centre for Remote Sensing of the Oceans, 6(3), 3-4 & 18, 1995. P.W. Vachon, S. J. Thomas, J. Cranton, H. R. Edel, M. D. Henschel, “Validation of Ship Detection by the RADARSAT Synthetic Aperture Radar and the Ocean Monitoring Workstation”, Canadian Journal of Remote Sensing, September 1998.
X. CONCLUSION There is a growing need to enforce international legislation applicable to fishing, maritime security and the environment. Satellite based SAR can significantly increase the effectiveness and efficiency of enforcement efforts. The combination of very large areas of interest and the requirement for timely data can only be met cost effectively by means of a dedicated reception station and an unlimited telemetry licence. The SENTRY station has proven to be well suited to remote deployment and high performance automatic operation, including the generation of ship detection products that can be rapidly transferred and validated remotely in an operations center. After one year of successful operation, the contribution of the system to the successful repression of illegal fishing has been proven with a sharp reduction of illegal vessels and reinforced by a successful arrest.
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