The paper has both a method and an application purpose. We think in fact that a concrete case instance can show, better than any other theoretic description, how the nowadays deregulation of the remote sensed imagery has deeply impacted the remote sensing methods.
In the case, we made a diachronic analysis of the natural and man made forest extensions and conditions in the Region Friuli Venezia Giulia (North East of Italy). We elaborated at this aim an historical series of remote sensed images. The satellite images have been classified and then investigated with a vegetation index which had
been applied only on the forest class areas, in order to get the tree health conditions.
