Earth observation (EO) data are mandatory data allowing to implement the surveillance phase in order to better address further search and Rescue mission. Several European EO systems are currently available, in particular Sentinel, COSMO and Copernicus.

Among the priorities of the Security dimension of Copernicus, Maritime Surveillance is one of the most important.

focuses on the combined use of different outputs: Space borne Earth Observation technologies with non-Space (airborne, terrestrial, etc.) sources, such as ground stations and sensors mounted on buoys, floats, vessels, and on research balloons, aircraft or drones. All this data, acquired through different sensors and elaborated by using different techniques need for a common framework in order to assemble them into useable, compatible and comparable information services. The combination among these different data is required since security requirements are very tight on satellite mission features such as revisiting time, latency etc. On the other hand, satellite data are able to provide data acquired on very wide areas and at a medium to very-high resolution becoming a valuable tool to monitor the Mediterranean Sea.

Data are not yet available online for Security applications, which are still in a development phase. These data will be used and evaluated into SARA project when available.

The Copernicus Security service is based on a series of research projects developed within the Framework Programmes 6 and 7 (FP6/FP7), funded by the EC and on ESA projects. For example, the MARitime Security Service, MARISS. The objective of MARISS was the development of a Near Real Time Traffic Monitoring services to enhance capabilities to track vessels back and forward at sea borders and identify them as friends or suspects. The service was based on the combination of information derived from satellite based EO with conventional data streams such as AIS, coastal radar, maritime patrol aircraft and intelligence sources for maritime border control and maritime situation awareness. The service can be used to detect unknown vessels and to evaluate the main vessel routes.

The Vessel Monitoring System (VMS) provides the position and identification of fishing vessels longer than 10 to 15 m. Likewise, the Automatic Identification System (AIS) gives the position and enables the identification of large merchant vessels. Usually, the smallest vessels are not equipped with VMS or AIS.

Nevertheless, small vessels can detected by using EO satellite data.

No more active ESA satellite SAR mission (ERS 1/2, Envisat) were extensively and successfully used to monitor the Mediterranean Sea in terms of oil pollution, evaluation of the main routes of commercial vessels and illegal trafficking (fishery and human). Today, ESA Sentinel-1 (C-band) continues the ESA missions of ERS and Envisat with a reduced revisiting time (6 days instead of 35). Sentinel-1 has proven to be suitable for the surveillance of the marine environment, including ship detection, for maritime security and mapping in support of emergency situations.

The automatic detection of ships based on SAR data benefits from a large number of scientific studies.

Optical EO imagery is also crucial for maritime security. Sentinel-2 is equipped with an innovative multispectral imager that acquires images with a swath width of 290 km using 13 spectral bands. The high-resolution optical sensor (4 spectral bands with 10 m spatial resolution) has a frequent revisiting capacity (5 days when both satellites will be on orbit).

Until data from Copernicus Security Service are unavailable we propose to exploit the use of Sentinel 1 and 2 and COSMO-SkyMed, if available, to detect vessels along the main routes.

Through the use of both the available Copernicus Security Services or new services based on Copernicus data it is possible to:

trace the main routes used by vessels between Africa and Europe. This task can be accomplished using both Optical and SAR satellite images.
detect vessels without transponder combining optical and SAR data with the service developed into the MARISS project.
detect people along the African coast waiting for boarding using very high resolution optical images.

These services will allow to decide the priority areas where drones will be more useful in case of sinking vessels. Considering the wide area to be monitored, this approach will allow a better use of the available resources focusing the research and rescue activities along the main routes where the probability of a shipwreck is higher.
More accurate and timely information will be obtained during the daylight period when optical, SAR and thermic images are useful. During the night and in case of cloud cover optical sensors are unusable thus data can be furnished only by SAR images.

This project has received funding from the European GNSS Agency (grant agreement No 776099),
under the European Union’s Horizon 2020 research and innovation programme GALILEO-3-2017.