The main goal of the Gfg2 coordinated action is to initiate the establishment of GNSS
(Global Navigation Satellite Systems) as a novel interdisciplinary field for observing
the Earth and its environment. Such fields are of outstanding social importance, and
may be described through contributions to the nine Social Benefit Areas to address
the current crucial problems of mankind (disasters, health, energy, climate, water,
weather, ecosystems, agriculture, biodiversity).

In parallel to the revolution in navigation, illustrated by the exponentially increasing
use of the U.S. American GPS (Global Positioning System) also the use for other
applications significant for different types of Earth observations has been realized.
Extremely accurate positioning is used to monitor the Earth’s crust, e.g. in areas
with high probability for earthquakes, or critical manmade structures such as bridges
and dams. Other prominent examples are the use of GPS observations for remote
sensing of the atmosphere (e.g. temperature, water vapour). Such data are already
operationally used to improve numerical weather forecasts world-wide. Another
application is to,make use of GPS signals reflected by water and ice surfaces. These
are examples of techniques currently in focus of international research and are
regarded to have immense potential in several of the above mentioned Social Benefit

The scope of Gfg2 activities is, however, far beyond these selected examples. GfG2
brings together GNSS experts with experts from all the nine social benefit areas to
establish new interdisciplinary fields with key importance for Earth observation. With
the availability of the new and modernized global navigation satellite systems (e.g.,
GPS-M, Galileo, QZSS, GLONASS, Beijdou) in parallel with the broader and broader
use of these in nearly all societal fields the importance of this field will open the doors
for new exiting applications.