For Digital Earth,an important priority is to integrate data from multiple sources.Interoperability and metadata are key instruments to reach such an objective.Interoperability is achieved by adopting and applying int...For Digital Earth,an important priority is to integrate data from multiple sources.Interoperability and metadata are key instruments to reach such an objective.Interoperability is achieved by adopting and applying international standards for service interfaces and data models.As far as geospatial information is concerned,interoperability recognizes three important,interrelated data concepts:feature,coverage,and map.The present work deals with Web services for coverage access.Coverage perspectives characterizing three geospatial communities-i.e.the Earth Science(ES),GIS and Digital Earth communities,are discussed.ES community requirements for coverage access services are presented and discussed making use of two methods concurrently:Critical Success Factor(CSF)analysis method supplemented through the use of Usage Cases.A CSF hierarchy and derived critical requirements and problems are introduced.An implementation approach consisting of four general principles is proposed.Access service categories emerging from the analysis are presented and their comparison with the present access services for the ES is discussed.展开更多
文摘For Digital Earth,an important priority is to integrate data from multiple sources.Interoperability and metadata are key instruments to reach such an objective.Interoperability is achieved by adopting and applying international standards for service interfaces and data models.As far as geospatial information is concerned,interoperability recognizes three important,interrelated data concepts:feature,coverage,and map.The present work deals with Web services for coverage access.Coverage perspectives characterizing three geospatial communities-i.e.the Earth Science(ES),GIS and Digital Earth communities,are discussed.ES community requirements for coverage access services are presented and discussed making use of two methods concurrently:Critical Success Factor(CSF)analysis method supplemented through the use of Usage Cases.A CSF hierarchy and derived critical requirements and problems are introduced.An implementation approach consisting of four general principles is proposed.Access service categories emerging from the analysis are presented and their comparison with the present access services for the ES is discussed.
