U.S. Geological Survey spatial data access

摘要: The U.S. Geological Survey (USGS) has done a progress review on improving access to its spatial data holdings over the Web. USGS EROS Data Center created three major Web-based interfaces deliver general public; they are Earth Explorer, Seamless Distribution System (SDDS), and Web Mapping Portal. Lessons were learned in developing these systems, various resources needed for their implementation. serves as fact-finding agency Government that collects, monitors, analyzes, provides scientific information about natural resource conditions issues. To carry out mission, managed since inception. Originally relying paper maps, now uses advanced technology produce digital representations of Earth’s features. products include both source derivative data. Derivative datasets Digital Orthophoto Quadrangles (DOQ), Elevation Models, Line Graphs, land-cover Raster Graphics, seamless National Dataset. These products, with automated processes, use aerial photographs, satellite images, or other cartographic such scanned maps With users can search multiple inventories through metadata queries browse DOQ imagery. They place orders make payment secure credit card transactions. Some be accessed SDDS. SDDS an ArcIMS map service interface identify user’s areas interest determine output format; it allows user either download actual directly small larger delivered media. Portal views national international interface. In addition, portal posts news new services available from USGS, many simultaneously published Environmental Systems Research Institute Geography Network. systems software tools expanded hardware meet requirements users. designed handle required workload relatively easy enhance maintain. give high level functionality help system conform industry standards. architecture is large amounts Internet traffic by systems. Last, customer support was answer questions, monitor e-mail, report problems. * Corresponding author