Concepts and Key Techniques for 30 m Global Land Cover Mapping

Global land cover(GLC)characterization and monitoring at fine resolution is a key task and big challenge for both earth observation and geomatics societies in the world.Recently the first operational 30 mGLC mapping project has been completed by China.It is based on the optimum selection and processing of landsatlike satellite imagery for full global coverage,service-oriented integration of all available reference data and auxiliary information,object-based precise land cover characterization,and knowledge-based data quality controlling.The key techniques developed include the multi-type imagery geometric processing and radiometric reconstruction,integration of heterogeneous data and external services,object-based thematic-layer classification,and knowledge-based spatio-temporal consistency verification.The technical guide lines and software tools have been further developed for supporting the operational30 mGLC mapping of the years 2000 and 2010.