“Earth Observation” is the set of space activities dedicated to photographing and scanning the planet with the scope of scientific elaboration, for the development of applications of various nature, such as environmental monitoring and analysis of situations and infrastructure. (in particular the study of natural disasters).
In the last years, the advent of new advanced technologies and the general concern for disastrous phenomena attributed to current changes in climate, have led to increased attention to this branch of space activities. It has helped to create applications that sit midway between scientific and applicative investigation, such as GOCE used to measure the terrestrial geoid, or in support of more efficient satellite data applications, like for example, ASI’s COSMO-SKYMED system.

GOCE Mission
Among the various missions underway or planned in which the primary objective is scientific, we have the ESA Mission named GOCE (Gravity Field and Steady State Ocean Circulation Explorer).
This is part of the “Earth Explorer” mission and does not pertain to any of the traditional categories belonging to Earth observation satellites; its importance rests on its capability to provide precise measurements of the Earth’s gravitational field thanks to the “gravimeter” instrument.
The GOCE satellite, has been launched in february 2009 from the Russian Plesetsk cosmodrome.
On the basis of the GOCE data several extremely accurate maps [1÷2 cm accuracy, 100km spatial resolution] of the geoid, through a global measurement of the gravitational field (accurate to 1 mGal).
Once available, this type of information will supply a precise reference point for hydrology, seismology, meteorology and geodesic study. The integration of these sources of data with geodetic data will carry a role of primary importance in obtaining a greater and more profound understanding of the earth’s gravity field in selected areas.
http://www.esa.int/SPECIALS/GOCE/index.html
http://www.esa.int/SPECIALS/GOCE/SEMY0FOZVAG_0.html

COSMO-SKYMED ASI Program
ASI’s COSMO-SKYMED program is currently the foremost program used for Observing the Earth.
The system actually operative consists of a 4 satellite constellation able to take 450 shots of the terrestrial surface in one day, being equal to 1,800 radar images in a 24 hour period.
The COSMO-SKYMED system observes the earth by means of SAR-X technology that offers the opportunity to obtain high resolution images (up to 1 m in spotlight mode). The results obtained are comparable to those of systems operating in the same optical bandwidth, but are not limited to conditions of clear skies or diurnal periods.
The fact that COSMO-SKYMED is composed of a satellite constellation guarantees the possibility to be able to observe the same region repeatedly (revisitation) so to obtain, updated and useful images that may be used to support intervention and in case of emergency.
For more information please go to the dedicated site
http://www.asi.it/it/attivita/osservazione_terra/cosmoskymed
http://www.asi.it/en/multimedia_en/photogallery/cosmoskymed

Applications
The precincts in which observation based on satellite systems are applicable are many; some of the more important ones are as follows:
  •   Preventive risk control
  •   Cartography
  •   Security
  •   Territorial monitoring and analysis
Already from this non-exhaustive list, we can see that possible “users” interested in the availability and use of the images obtained are not limited to the multiple government and public bodies (Ministry of Defense, Civil Protection, Ministry of Agriculture and others) but, for commercial bodies as well. (Construction companies, Forestry/Agriculture, and others).
The area of greatest significance, however, is to support the management of emergency and security.

PHOTO: NASA/ESA/TELESPAZIO