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Overview

Overview. Searching for data. Web search engines NSDI GeoSpatial Data Clearinghouse USGS GeoData site University of Washington Map Library GeoSpatial Data Archive. Importing data. ARC/INFO interchange file SDTS files. USGS DEM data USGS DLG data. Searching for data. Web search engines

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Overview

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  1. Overview Searching for data Web search engines NSDI GeoSpatial Data Clearinghouse USGS GeoData site University of Washington Map Library GeoSpatial Data Archive Importing data ARC/INFO interchange file SDTS files USGS DEM data USGS DLG data

  2. Searching for data Web search engines NSDI GeoSpatial Data Clearinghouse USGS GeoData site University of Washington Map Library GeoSpatial Data Archive

  3. Searching for data: Web search engines The primary method for searching for general data on the net Keyword searching Logical parsing of searches Search is far and wide Possible to use meta-searchers Graphical results Low precision

  4. Searching for data: Web search engines Search“GIS&data” Results are good

  5. Searching for data: Web search engines Search “GIS&data&Washington” Results are bad

  6. Searching for data: Web search engines Why are web search engines not the best tool for searching GIS data? Spiders only find and index keywords, not meaning Searching for keywords is not efficient Too many erroneous matches Not a true database query No spatial coordinates in normal search engines Too many dead ends and broken links No standard format for searching various engines

  7. Searching for data: NSDI GeoSpatial Data Clearinghouse (GDC) Better methods are needed for searching for GIS data Federal agencies mandated to increase access to geospatial data National Spatial Data Infrastructure (NSDI) Federal Geospatial Data Committee Development of common search engine Standardized approach Queryable databases (Z39.50 international library standard) Specific server network built on top of the Network Metadata is the keystone

  8. Searching for data: NSDI GDC: Metadata Content-standardized metadata is the foundation of a robust searching tool Records for individual data sets contain data for specific fields, e.g., Title Abstract Spatial extent Data type Currency of time scale Source scale Developer/Contact information

  9. Searching for data: NSDI GDC: Indexed databases Metadata records are indexed into international library Z39.50 standard databases Specific sites containing indexes (nodes) are registered with search server sites Searches can be limited to individual nodes or to many nodes Databases are searchable across TCP/IP networks Searching functions are imbedded in web interfaces Results are displayed in web pages

  10. Searching for data: NSDI GDC: Searching Search by place name orgeographic location

  11. Searching for data: NSDI GDC: Searching Search by time period Search by keyword in various fields

  12. Searching for data: NSDI GDC: Searching Select node to search

  13. Number of hits is displayed Individual records can be browsed • Searching for data: NSDI GDC: Results

  14. Searching for data: NSDI GDC: Results Individual record titles can be browsed

  15. Particular data are hyperlinked • Searching for data: NSDI GDC: Results Individual records can be read

  16. Searching for data: NSDI GDC: Results Find out where to get copies of the data

  17. Searching for data: USGS GeoData site A tremendous amount of data area available for “free” Data sets representing USGS topographic quadrangles Data from paper maps converted to digital format DEM (raster elevation) data Vector data for a variety of themes Variety of source scales

  18. 7.5’ (1:24,000) topographicquadrangle vector data series Always review 00README files • Searching for data: USGS GeoData site

  19. Individual files are downloadable • Searching for data: USGS GeoData site: Downloading Interactive quadrangle searching Text-only searching also available

  20. Searching for data: University of Washington Map Library GeoSpatial Data Archive (WAGDA) Staffed by “GIS Librarian” Jenny Stone Should be your first stop when searching for GIS data Depository library Suzzallo Library basement Data repository for Washington and PNW data On-line and off-line data sets City of Seattle GIS database 10 m USGS DEMs Large collection of paper maps & aerial photos

  21. Searching for data: WAGDA Web page

  22. Searching for data: WAGDA Web page

  23. Importing data ARC/INFO interchange file SDTS files USGS DEM data USGS DLG data

  24. Importing data: ARC/INFO interchange file ARC/INFO has been a leading software Very common file format Known as “interchange,” “export,” or “E00” file Easy to transfer from machine to machine or across file system; easy to distribute via the Network Can be imported into ARC/INFO format for use in ArcView

  25. some of these files are associated with this data set • Importing data: ARC/INFO file structure

  26. Importing data: ARC/INFO file structure Problematic file structure for file management Directories for ARC/INFO data sets cannot be altered, copied, or moved arbitrarily Interchange file “packages” coverage directoryand info files into a single interchange file

  27. Importing data: ARC/INFO file structure: Importing menu access to importing application

  28. GUI-controlledimport function data imported asARC/INFO coverage • Importing data: ARC/INFO file structure: Importing

  29. Importing data: SDTS files USGS digital elevation model (DEM) data USGS digital line graph (DLG) data

  30. Importing data: SDTS files: USGS DEM data publicly available data sets distributed by USGS in SDTS file format public-domain tools for conversion from SDTS

  31. public-domain converter input SDTS output DEM • Importing data: SDTS files: USGS DEM data

  32. Importing data: SDTS files: USGS DEM data ArcView imports USGS format DEMs

  33. Importing data: SDTS files: USGS DLG data vector format data publicly available data sets distributed in zipped or SDTS file format public-domain tools for conversion from SDTS to DXF ARC/INFO or other commercial softwarefor full conversion of SDTS to GIS data sets

  34. Importing data: SDTS files: Importing STDS DLG to DXF

  35. Importing data: SDTS files: Importing STDS DLG to ARC/INFO coverage

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