Upland areas of the UK are facing increased pressures from a range of changing environmental conditions, such as atmospheric pollution, increased nitrogen deposition, overgrazing and inappropriate management (UK_biodiversity 2002), with consequent impacts upon the status, composition and extent of important vegetation habitats. Of particular concern is the loss of biodiversity and upland habitat within protected areas, such as National Parks and Environmentally Sensitive Areas (ESAs). Information on the extent, condition and changes to species composition is vital for managing and conserving protected areas (Maas, 1991). Previous attempts to map species and habitats in upland areas have generally relied upon field survey (such as the Phase 1 habitat survey completed across the UK in 1990) which have yielded poor results, at a high financial cost and are not suited to frequent and fast update (Cherill and McClean, 1999). There is a lack, therefore, of accurate information relating to the extent and distribution of upland vegetation for extensive areas across the whole of the UK (Backshall et al., 2001). Clearly remote sensing and aerial photography offer potential to acquire this information but have so far been limited operationally.