Geoscience Reference
In-Depth Information
Chapter 19
Remote Sensing and
Earth Observation
Heiko Balzter
Earth Observation has become more and more prominent in many aspects of con-
temporary environmental research. Earth Observation describes the process of
remotely measuring certain properties of the Earth system, like atmospheric gas
concentrations, aerosol optical depth, land cover, forest fi res or glacier velocity.
Observations from aircraft and satellites provide spatially explicit and often multi-
temporal geographical datasets that can be used for detecting, monitoring and
mapping environmental changes. The increasing accessibility of Geographical Infor-
mation Systems (GIS) have made it possible to base decision-making processes
increasingly on remotely sensed observations since imagery can be used to provide
data layers in GIS databases.
International organisations and national departments increasingly take up
remotely sensed data in their everyday procedures. An example is the United Nations
Food and Agriculture Organisation (FAO), which deploys remote sensing techniques
for early warning systems, environmental monitoring and rapid assessment of crop
growth conditions, as well as for natural resource inventory, monitoring and man-
agement at local, national, regional and global scales. One such application is the
Global Forest Resources Assessment from 1990, 2000 and 2005. For the 2010
assessment a comprehensive global remote sensing survey is planned (Ridder, 2007).
Since 1988, the FAO has also operated the Africa Real Time Environmental Moni-
toring Information System (ARTEMIS). This system acquires and processes hourly
estimates of rainfall and vegetation index (NDVI) images in (near) real time using
Meteosat and NOAA data. ARTEMIS covers the whole African continent. The 10-
day and monthly data products are used to identify areas in which food security
might be at risk or where desert locust control measures may be necessary.
Data from Earth Observation is now central to environmental research and
to a number of international science programmes. The International Geosphere-
Biosphere Programme (IGBP) views Earth Observation as vital. Dr Will Steffen,
Executive Director of IGBP, told the Earth Observation Summit in Washington in
2003 that 'the Earth has a number of “Achilles' heels” that are particularly sensitive
to human activities. Examples include the Gulf Stream in the North Atlantic, the
