cfr 250/590 introduction to gis, autumn 1999 data search & import © phil hurvitz,...
TRANSCRIPT
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
find_data 1
Data Search & Import
Overview
• Web search engines• NSDI GeoSpatial Data Clearinghouse• USGS GeoData site• University of Washington Map Library
GeoSpatial Data Archive
• Searching for data
• Importing data
• ARC/INFO interchange file• SDTS files
• USGS DEM data• USGS DLG data
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Searching for data
• Web search engines
• NSDI GeoSpatial Data Clearinghouse
• USGS GeoData site
• University of Washington Map Library GeoSpatial Data Archive
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
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
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Searching for data: Web search engines
• Search
“GIS&data”
• Results are good
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Searching for data: Web search engines
• Search
“GIS&data&Washington”
• Results are bad
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
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
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Searching for data: NSDI GeoSpatial Data Clearinghouse (GDC)
• National Spatial Data Infrastructure (NSDI)
• Federal Geospatial Data Committee
• Better methods are needed for searching for GIS data
• Federal agencies mandated to increase access to geospatial data
• 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
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
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
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
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
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Searching for data: NSDI GDC: Searching
• Search by place name orgeographic location
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Searching for data: NSDI GDC: Searching
• Search by time period
• Search by keyword in various fields
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Searching for data: NSDI GDC: Searching
• Select node to search
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Searching for data: NSDI GDC: Results
• Number of hits is displayed
• Individual records can be browsed
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Searching for data: NSDI GDC: Results
• Individual record titles can be browsed
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Searching for data: NSDI GDC: Results
• Individual records can be read
• Particular data are hyperlinked
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Searching for data: NSDI GDC: Results
• Find out where to get copies of the data
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
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
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Searching for data: USGS GeoData site
• 7.5’ (1:24,000) topographicquadrangle vector data series
• Always review 00README files
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Searching for data: USGS GeoData site: Downloading
• Interactive quadrangle searching
• Individual files are downloadable
• Text-only searching also available
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
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
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Searching for data: WAGDA Web page
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
find_data 22
Data Search & Import
Searching for data: WAGDA Web page
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
find_data 23
Data Search & Import
Importing data
• ARC/INFO interchange file
• SDTS files
• USGS DEM data
• USGS DLG data
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
find_data 24
Data Search & Import
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
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Importing data: ARC/INFO file structure
some of these files
are associated with this data set
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
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
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Importing data: ARC/INFO file structure: Importing
menu access to importing application
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
• GUI-controlledimport function
Importing data: ARC/INFO file structure: Importing
• data imported asARC/INFO coverage
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Importing data: SDTS files
• USGS digital elevation model (DEM) data
• USGS digital line graph (DLG) data
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
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
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Importing data: SDTS files: USGS DEM data
public-domain converter
input SDTS output DEM
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Importing data: SDTS files: USGS DEM data
• ArcView imports USGS format DEMs
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
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
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Importing data: SDTS files: Importing STDS DLG to DXF
© Phil Hurvitz, 1999-2000
CFR 250/590 Introduction to GIS, Autumn 1999
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Data Search & Import
Importing data: SDTS files: Importing STDS DLG to ARC/INFO coverage