Άσκηση 3: Ανίχνευση και παρακολούθηση πολυχρονικής αλλαγής - συνέχισε   Change detection result obtained by subtracting the filtered lava classification of 2001 from that of 2003.   Band combination 4-5-3 of Landsat images taken in 1975, 1978, 1987, 1992, 2001, 15 January 2003, and 31 January 2003. Changes from one year to the next are indicated by red ellipses.