Terrafirma is one of
ten services being supported by the European Space Agency's
(ESA) Global Monitoring for Environment and Security (GMES)
Service Element Programme. Terrafirma provides a ground
motion hazard information service, distributed throughout
Europe via national geological surveys and institutions.
The objective of this service is to
Terrafirma is based upon the
revolutionary remote sensing technique of Persistent Scatterer
Interferometry which has the power to map millimetric ground
motion phenomena from space. PSI involves the processing
of 50+ radar scenes from an archive dating back to 1991
to identify networks of reflecting ground features, such
as buildings, bridges and other structures, against which
precise phase measurements can be made over time. The results
provide unique, wide-area maps of ground and building motion
that can be difficult if not impossible to detect by conventional
means. The service currently focuses on urban subsidence
and landslides but will eventually include earthquake zones,
coastlines and flood plains.
Terrafirma is operating
in three discrete stages of 0-2, 2-5 and 5-10 years. The
first two-year Stage 1 (which ended in 2005) was concerned
with consolidation of both service providers and users.
In November 2005 Terrafirma entered Stage 2, concerned with
rolling-out the service across all Member States of the
EC. During this stage, processing equally covering all of
the EU25 Member States will be conducted along with the
processing of seven landslide products within Greece, Italy
and Switzerland. Stage 3 began in December of 2009 and will continue until the end of 2012. This third and final stage offers services under the thematic lines of Coastal Lowland Subsidence & Flood Defense, Hydrogeology and Tectonics and offers a new Wide Area Service.
Feel free to download a guide to the use and understanding of Persistent Scatter Interferometry in the detection of terrain-motion: