IEEE Geoscience and Remote Sensing Magazine - September 2016 - 35

agencies) and stakeholders from the EO and information
technology communities. In general, the collected feedback
was very encouraging, i.e., most users found the applications
very useful, specifically when it concerned stakeholders that
need fire-monitoring products as part of their daily work
practice (e.g., the Greek Ministry of Environment, Energy, and
Climate Change; the Italian civil defense agency; or foresters
in local administrative units). The value of applying semantic
queries for the thematic refinement of the hot-spot products
has been appreciated by the EO community.
The users can access the service using a web-based interface that is designed to meet the needs of the target user
base as described previously. The most important features
of this interface are that it visualizes all current hot spots
real time, along with useful auxiliary information (e.g., affected municipalities); it allows for retrieving and watching
historic data about fires that occurred in the past; and the
processing chain (e.g., the refinement operations) are executed in the background in a fully automatic way, presenting the results to the users.
rELatED WorK
In related work, in the context of the LOD2 project (http://
lod2.eu/Welcome.html) [4], a software stack was developed
that comprises a number of tools for managing the life cycle
of linked data. In the TELEIOS and LEO projects, we extended this software stack to develop the life cycle of linked EO
data, as presented in this article.
In the area of semantic-enabled search engines, the most
popular platforms are RARE (http://wiki.services.eoportal.
org/tiki-index.php?page=RARE+Project) and Semantic-Web
for Mediated Access Across Domains (http://wiki.services.
eoportal.org/tiki-index.php?page=SMAAD). RARE permits
searching for EO products by entering terms used by the users in their application domains. In SMAAD, the focus is
on the interoperability between the available ontologies,
i.e., the web interface allows the users to navigate ontologies and terms that characterize EO products. RARE and
SMAAD rely on a preparatory work (i.e., ontology mapping,

Response Time (ms)

104
Store
Municipalities
Delete in Sea

Invalid for Fires
Refine in Coast
Time Persistence

103

102

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June and July 2012

FiGUrE 8. The MSG-1 acquisitions.
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ieee Geoscience and remote sensinG maGazine

EO product characterization, and reasoning rules) that is
barely reusable in other systems without integrating the
original software components. Also, they require the EO
products to be annotated with controlled vocabularies that
have not been standardized. These limitations prevent other
organizations (e.g., scientific communities and commercial
companies) from implementing their own compatible solutions that are adapted to their own requirements and application domains. This work was advanced in the ProdTrees project (http://wiki.services.eoportal.org/tiki-index.
php?page=Prod-Trees+Project) in the context of which the
netCDF product format and vocabulary were extended to allow the storing of metadata that better describe the products
and, in particular, EO products. These developments were
implemented as extensions to the RARE platform. Furthermore, the work described in [21] reports a technique for introducing semantic tags to image content.
coNcLUsioNs
In this article, we discussed how big, linked, and open EO
data can be managed using the technologies in the TELEIOS/
LEO software stack. The software stack and life cycle described are now being applied in several use cases in the context of the EU FP7 project MELODIES (http://www.melodiesproject.eu/). We also showed how these technologies can be
used to implement the fire-monitoring service of the NOA.
acKNoWLEDGMENts
This work was funded by the FP7 projects TELEIOS (257662),
LEO (611141), and MELODIES (603525).
aUtHor iNForMatioN
Manolis Koubarakis (koubarak@di.uoa.gr) is a professor in
the Department of Informatics and Telecommunications,
National and Kapodistrian University of Athens, Greece. He
has published more than 140 papers that have been widely
cited in the areas of artificial intelligence (especially knowledge representation), databases, the semantic web, and linked
data. His research has been financially supported by the European Commission, the Greek General Secretariat for Research, the European Space Agency, and industry sources.
Kostis Kyzirakos (kkyzir@di.uoa.gr) received his Diploma in engineering from the School of Electrical and Computer Engineering, National Technical University of Athens,
Greece, and the Ph.D. degree in computer science from the
Department of Informatics and Telecommunications, University of Athens, Greece. He has participated in projects funded
by the European and the Greek General Secretariat for Research and Technology. He is one of the main developers of
the open-source semantic geospatial database management
system (DBMS) Strabon and the open-source publishing
tool GeoTriples that automates the publication of geospatial
data as Resource Description Framework graphs. During his
Ph.D., he studied and proposed how to represent and query
geospatial data in the semantic web, published various geospatial data sets as linked geospatial data, and implemented
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http://wiki.services.eoportal.org/tiki-index http://http:// http://www.lod2.eu/Welcome.html http://www.melodies http://www.project.eu/ http://wiki.services.eoportal http://www.wiki.services http://www.eoportal.org/tiki-index.php?page=SMAAD

Table of Contents for the Digital Edition of IEEE Geoscience and Remote Sensing Magazine - September 2016