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Frequently Asked Questions – Quick FAQ’s

  
How does the EMSA satellite service work?
The EMSA satellite service offers extensive surveillance of European waters for oil spills by using radar images acquired by Synthetic Aperture Radar (SAR) sensors on polar orbiting satellites. SAR sensors have the capability to detect oil slicks on the sea surface in darkness as well as daylight hours and to see through clouds. These sensors send out short bursts of microwave energy and then record the strength and origin of the returning reflections. SAR sensors can estimate the roughness of a target surface which is captured in the radar reflection patterns of an image. An oil slick at sea “smoothes” the water surface and thus reduces the radar backscatter to the sensor. This creates a darker signature in the image which, after automatic processing, experienced analysts can then interpret as a possible oil slick. Many other factors affect the interpretation of an image such as wind, the presence of sea ice or naturally occurring algae blooms and these need to be taken into account at the time of analysis. Such analysis can be provided by or via the Agency. The final verification of the possible slick needs to be done by in-situ means such as vessel or aerial surveillance. These SAR images are rapidly transmitted to the nearest ground station, where they are processed and interpreted by experienced image analysts. If an oil spill is detected the image and alert information will be sent to the pollution control authorities of Member States within 30 minutes of satellite overpass of the area of interest. National aerial and vessel surveillance patrols can then target this area to verify the spill and if possible identify the polluter. By complementing national aerial and vessel surveillance with satellite images, a more cost effective use of these expensive resources is achieved. Wide area surveillance coverage using satellite images (up to 405 km x 405 km for one image) will lead to a stronger deterrence of potential polluters.
What information can the EMSA satellite service provide?
The service will provide a range of information including:

- Oil spill alerts to Member States and rapid delivery of all available satellite images over the area of interest,
- Slick position/extent/pattern/shape,
- Assimilated meteorological wind and wave data,
- Local wind and wave data derived from the SAR image. Alerts to Member States will be delivered by email or phone sms. Delivery of the satellite images and reporting of information will be available through the EMSA web interface directly to the operational pollution control authorities in Member States and the Commission. Support for image interpretation is available from experienced image analysts. In addition, extended monitoring of the area of interest by satellite images for the duration of the spill event can also be set-up. The satellite images do not provide information on:

- Thickness of the slick /volume of oil on the sea surface.
- Oil under the sea surface.
Certain environmental conditions can interfere with the detection of slicks however they are well characterised by image analysts. Such conditions, which will be taken into account during the interpretation of the SAR images, include very high or very low wind speed (slicks can be detected with a wind between 2-12 m/sec) and/or the presence of sea ice or algae blooms. EMSA will continue to develop other integrated information sources into the EMSA service beyond the 2007 time frame.
What is the added value of a pan-European operational system for marine oil slick detection and surveillance?
While some Member States already use satellite data to support marine surveillance activities on a national or regional level, other Member States have not taken action in this field so far. To develop a common sustainable European system, EMSA would like to transfer expertise from regions with experience in satellite surveillance to regions with no operational experience in this field. It has been demonstrated, through examples from both HELCOM and the Bonn Agreement, that satellite services operated at a regional level allow co-ordination of surveillance resources and an improvement in cost efficiency for aerial and vessel surveillance. In addition, the purchase of a large volume of imagery creates a cost reduction due to economies of scale. A common approach to oil spill surveillance at European level using compatible data standards and methodologies will support the development of robust statistics for oil pollution monitoring and create baseline measurements that may be extended in the future. For the detection of polluters, a European level system of continuous spill information with vessel traffic data should become operational in 2008.
Can EMSA satellite monitoring services support Member States efforts to deter deliberate discharges?
One of the purposes of Directive 2005/35/EC is to ensure that persons responsible for illicit discharges are subject to adequate penalties. EMSA is tasked to support the Member States and the Commission for the implementation of the Directive. Although the needs for routine operational surveillance and emergency situations are different, satellite imagery complements other remote sensing resources such as dedicated aircraft. A common information infrastructure between EMSA and the Member States’ pollution control authorities, eventually integrating Automatic Identification System (AIS) information and numerical modelling for drift forecast and hindcast, will improve information sharing and operational means for tracing polluters and supporting further prosecution, fully organised and executed by the Member States themselves.
How can EMSA assist in satellite monitoring and surveillance during an accidental oil spill?
In case of an accidental spill, Member States and/or the European Commission will normally activate the International Charter “Space and Major Disasters”. During 2007 EMSA will be ready to offer additional services upon request. The Agency may be asked to assist in analysing satellite imagery, to help coordinate and order all possible satellite imagery to continuously monitor the evolution of an accidental spill as well as to assist in applying forecasting computer models.
Which countries can use the CLEANSEANET service?
The CLEANSEANET service is available to all EU Member States, EFTA States, Acceding Countries and the European Commission.
How do you define the area to be monitored by SAR imagery?
In order to define the area(s) to be monitored, EMSA provides a GIS tool based on an Open Source. This solution automatically loads all the required layers of information constituting a simple way to acquire information from the Coastal States. This GIS information will then be used as the basis for the EMSA acquisition planning. In order to request the GIS tool please use the email address below. It is important to note that the GIS tool does not allow the definition of individual satellite scenes
Which satellite sensors are used by the CLEANSEANET service?
CLEANSEANET is using the European Space Agency ASAR sensor onboard the ENVISAT satellite together with the Canadian Space Agency RADARSAT-1 sensor. RADARSAT-2 images will also be used once the satellite is launched and operational (beginning of 2008). Optical imagery, from MODIS-Aqua, will also be available to provide additional information and fully complement the analysis.
04/13/2007 17:49


  
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