Reliable global land cover information is necessary for global change studies and global/continental land use management and planning. In order to meet this needs, global four-minute grid land cover data set was produced using global 8-km 10-days composite AVHRR NDVI data for one year in 1990. The data set production was performed by the following steps. (1) A new land cover classification system with hierarchical structure was proposed. (2) Ground truth data base of four-minute resolution was prepared with ground truth source information. (3) Combined classification method was applied using ground truth data, extended ground truth data, and a result of binary decision tree method.
The produced land cover data set and ground truth data set is available from the authors.