Change detection techniques

The term "change detection" defines the process of identifying changes in an object or a phenomenon, occurring in a particular time interval. The basic premise of change detection analyses carried out using remote sensing data is that a change in land cover or surface observed by a sensor corresponds to a change in the spectral response, and that this change is effectively distinguishable from spectral variations due to other factors, such as the atmospheric conditions effects at the time of acquisition, or soil moisture conditions, or other differences in the acquisition process of the data.

Change detection and flood damage: the North-East of Bangladesh submerged by monsoon floods in 2001;
left: before the flood; center: after the flood. On the right the map of changes that allow you to identify
the flooded areas and the damaged infrastructure.