The IGBP DISCover confidence sites and the system for terrestrial ecosystem parameterization: Tools for validating global land-cover data

The IGBP Validation Confidence Site database provides a set of 379 land-cov er maps, each containing an IGBP Core Validation sample. Each map is 448 km (2) in area and is delineated and labeled by photointerpretation of Landsat or SPOT satellite imagery at a scale of 1:125,000. Within each map, land-c over types and polygons are assigned descriptive labels and parameter codes for vegetation attributes, including life form, cover, height, and phenolo gy for canopy and ground layers. These attributes are a subset of parameter s defined by the System for Terrestrial Ecosystem Parameterization (STEP), a site model and database that characterizes land surface and vegetation fo r use in global algorithm training testing and validation of land-cover dat a. Because the maps are linked to the core samples, they provide a large, c onsistent dataset that is stratified to represent equally all of the world' s major vegetation form classes and land-cover types. The confidence site d atabase has three primary applications: (1) as a set of validation benchmar ks for alternate regional or global land-cover classifications emphasizing vegetation attributes, (2) as a secondary information source for studying c ore sample accuracy issues, and (3) as a source of training and test sites for regional and global supervised classification of coarse-resolution sate llite imagery.