Though, in the broadest sense, remote sensing is the acquisition of information of an object or phenomenon by a device that is not in physical contact with object of interest. In practice, this term usually refers to remote observation of planet Earth.
The list of civil remote sensing application has been quickly growing over last decades and it is ranging from geography, geologic explorations, oceanology, meteorology, agricultural and environmental monitoring and assessment, to prevention, monitoring and aftremath evaluation of natural disasters such as earthquakes, floods, huricanes, droughts etc. This broad range of applications is based on variety of detection and data processing methods. The most of remote sensing techniques make make use of emitted or reflected electromagnetic radiation of the object of interest in a certain frequency domain (infrared, visible light, microwaves). This is possible due to the fact that the examined objects (plants, houses, water surfaces, air masses ...) reflect or emit radiation in different wavelengths and in different intensity according to their current condition. 
The aim of the PECS-GRID project is developement of a prototype of GRID based functionality for processing Synthetic Aperture Radar data acquired by European Space Agency (ESA) ERS and ENVISAT Earth observation satelites.
Beside the general functionality, the planned outputs shall be also different test cases (application prototypes) of relevance for the remote-sensing community such as Europe mapping, flood damage assessment, forest/non-forest classification which should prove effectiveness of the developed system.
|||Wikipedia - Remote sensing|