Earth Observation in the frame of EO-MINERS - Earth Observation methods
The scope and what constitutes Earth Observation are not very well defined and delineated. Any extensive property for which spatially distributed data are available could be included. Clearly data in the candidate indicator categories I, J and K would fall into this category. As will be pointed out below, however, they are typically not accessible to physical or chemical measuring techniques. The typical mode of gathering is the analysis of pre-existing economic and the like data or through targeted interviews, polls and similar socio-economic techniques. A review of the EO-MINERS candidate indicators will show that in many cases spatially distributed socio-economic properties have to be put in relation with some physical properties of the site or region under investigation. These relations will then reveal, for instance, risks or impacts.
The classical method to visualise such relations distributed in space is to superimpose maps of the different variables under consideration. Digital computing, algorithms to store and manipulate large databases and refined computer-supported visualisation techniques help in both, the data analysis as well as the presentation of the results to the stakeholders concerned.
GIS - Geographical Information Systems are the tool of today for this kind of multi-dimensional data analysis and decision support. The first GIS were developed in Canada in the 1960s for use on mainframe computers. Today, GIS software can be even run on personal computers. Many of the techniques discussed in the previous sections either directly deliver spatially related data, while in most other cases the databases used to manage say analytical data also provide the necessary information on sample locations. In other cases valuable information, such as older topographic maps, can be digitised and either used as bit image or be vectorised for more flexibility in use.
The principle of GIS (www.stlawu.edu).