Geodata Discovery Working Group

This is a Working Group started by the Public Geospatial Data Committee.

While OSGeo can consider hosting sets of public geodata, (and for the purposes of offering maintained packages of high-quality data for education and demonstration, it probably will), we can compile a set of best practises and references to good prior art for building and maintaining collections of data and metadata.

Focus

• Metadata for collections of geographic information.
• Providing best practise and prototypes for geodata search facilities
• Help with providing input into the OSGeo repository/services at http://osgeo.telascience.org/
• Providing 'catalog'/discovery/search services as part of OSGeo activities in promoting access to public domain and open licensed bodies of data.

Participants

• Jo Walsh
• Schuyler Erle
• David Bitner
• Perry Nacionales
• Markus Neteler
• Arnulf Christl
• Bob Wang
• Oscar Cantán
• Stefan Keller
• please add yourself

Existing (Meta) Search Projects and Related Efforts

Search Services:

• (Meta) Data Catalogues / Data Repositories
  • Mapdex is "a global Index of 2,018 servers, serving 37,168 map services, containing over 400,000 GIS Layers, covering more than 4,000,000 columns!"
  • GeoTorrent hosts BitTorrents of shapefile/TIFF format data.
  • GeoNetwork "Find Interactive Maps, GIS datasets, Satellite Imagery and Related Applications"
  • DLESE Collection System offers a metadata repository and editor and supports OAI-PMH as data provider and harvester
  • Geo Meta Data Base (GMDB) - Metadata repository and editor based on ISO 19115/119 Metadata and Dublin Core with XML export and OAI-PMH data provider support (german only)
  • GDI Portals (country specific): US, UK, D, A, CH, LI, F, ...
• (Meta) Search Engines:
  • geometa.info - search engine for geospatial services, data and documents combining structured and unstructured data (currently german only)
  • Google search using 'allinurl' parameter

Lists:

• Web Services lists:
  • http://www.skylab-mobilesystems.com/ger/wms_serverlist.html simple WMS service URL list
  • http://www.refractions.net/white_papers/ogcsurvey/ Automated OGC Survey on the Web (WMF, WFS, ...)
  • http://geometa.info/search.jsp?query=type%3Awms WMS search engine
  • http://exploreourpla.net/maps/
  • Orthophotography Annotated list of Orthophotography WMS Services
• US data servers:
  • http://datagateway.nrcs.usda.gov/

Public Datasets for Possible Mirroring or Distribution

Gazetteer Data

... basically placenames with coordinates ...

• Geonames.org gazetteer (includes NGA GNS Gazetteer)
• WorldWind Placenames (markusN can provide PERL to read this)

Vector data

• VMAP0 - 1:1Mio, very generalised vector data for many features, around 70 layers (already at telascience)
• World map for APRS, 1:1.1mio
• GSHHS - world coastlines, different scales available
• TIGER/Line (USA) - street and addressing data for the US
• RNF (Canada) - street and addressing data for Canada
• OpenStreetMap - data available through a HTTP based XML interface. They've also been getting requests for shapefile and GML output of their data.

Raster data

• DEM
  • SRTM V2
  • ETOPO2
  • TOPEX: SRTM30 (with GTOPO30 data for high latitudes where SRTM data are not available)
  • NOAA TCM LIDAR / IfSAR
• Satellite Data
  • Landsat (OnEarth mirror already at telascience)
  • Blue Marble / Blue Marble Next Generation (mirror already at telascience)
  • ASTER (from GLCF)
  • MODIS (from NASA EDC)
  • USGS Urban Orthos (URL?)
• Maps derived from Satellite Data
  • Nested Imagery Layer (Best of -- resolution -- with seamless zoom through multiple levels)
  • AVHRR Landuse Map from GLCF
  • natural earth
  • City lights
  • HydroSHEDS - Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales

Wishlist for Public Datasets

• Orthophotos
  • Possible sources:
  • http://www.fgdl.org/download/index.html
  • http://datagateway.nrcs.usda.gov/

Search Protocols

• GIS specific:
  • OGC's CSW 2.0 (work in progress...) (ISO/OGC's "ISO19115/ISO19119 Application Profile for CSW 2.0"). See a comparison between CSW and OAI-PMH
  • OGC's WFS (profile) serving (profiled) ISO 19115/19119 metadata format...?
  • 'Lean and mean' proposals on project level...
    • Simple Catalog Interface
• Related search protocols - possibly to be profiled or specialized by geoinformation requirements:
  • Open Archives Initiative Protocol for Metadata Harvesting 2.0 (OAI-PMH)
  • Search/Retrieve via URL (SRU/SRW)
  • OpenSearch proposal from A9
  • Z39.50 ANSI/NISO standard protocol
  • ebXML/ebRIM Messaging Service 2.0

Hosting Plan

(placeholder for an initial hosting plan sketch)

See Also

• Geodata Packaging Working Group
• Geodata Licensing Working Group
• WMS Tile Caching proposal
• Geodata processing at telascience.org