Geodata Repository

The notes on the Talk:Geodata_Repository Talk page for this page describe the background to this effort

A full list of suggestions for public domain data sets that are nice-to-haves is maintained at Geodata Discovery Working Group.

Getting involved

The geodata repository has a dedicated blade server at telascience - cf SAC Service Status. Right now this is geodata.telascience.org ; we need to get an osgeo.org domain pointed to it. The plan is to have something very much up, running and demoable by FOSS4G.

How you can help

• Offer feedback on the Geodata Metadata Requirements - if you have a dataset you would like to contribute, does this model express it adequately?
• Write or contribute an example Simple Catalog Interface
• If you would like to install software and/or data on the repository machine, please talk to the good people at SAC or visit #osgeo and #telascience on irc.freenode.net to find out how to get an account and get started

Who is involved now

• Jo Walsh is working on the backend data store and machine level metadata interfaces (also presenting this material at FOSS4G 2006)
• Chris Schmidt is helping with an OpenLayers-based browsing interface
• Schuyler Erle is helping with web service / application glue
• Sean Gillies' OWSLib is, half-beknownst to him, a big part of all these applications - see the OWSLib API user stories at http://trac.gispython.org/projects/PCL/wiki/OwsCapabilitiesUserStory
• Markus Neteler is contributing data processing code and resources as part of the GRASS data packaging effort
• Norm Vine is providing a point of contact for administering the system and general reality-checking to all involved.

Interface Design

In order to be useful to people, a geodata repository needs a way for users to become quickly + easily informed as to what kind of data they're getting: metadata about the data, and the quality/quantity of data involved.

For Raster images, one way to do this is to include an extent-wide image of the data -- http://openlayers.org/gallery/ has screenshots which show some of what I mean where, although more directed towards applications. By having a whole-extent screenshot overview, users can quickly and easily see what they're getting. Additionally, assuming this data is to be made available as WMS, setting up an OpenLayers instance to allow users to browse the rasters and see at a more detailed level would be beneficial.

Vector data/attribute data would also need to be described, in text or some other way. http://freemap.in/world/ is an example of a browsable map which displays attribute data -- clicking on a country fills the sidebar with data. This interface was set up in about 20 minutes, and given decent map files, this kind of set up could be largely automated, allowing users to (again) get an overview of the data they're looking at before they download it or set it up on their own servers.

Data sources

Sources of public geodata for initial setup in a repository.

Data at SDSU

• plus we have a PostGIS, GeoServer and MapServer installation running at

zuluvis.sdsu.edu  says NHV with VMap0 in it!  - see below.

VMap0 - and some other vector data

• There's a PostGIS server on 'zuluviz.sdsu.edu' for storaging different flavours of vector data. Current datasets include: VMap0, VMap1, AptNav, GSHHS, SWBD, MGRS, TIGER, GeoNames, FGSODB - see below for further explanation.

• Short explanation of available datasets (to be extended):
  • VMap0: Selected subsets of VMap0 polygons, lines and points, starting with a selection that has proven to be useful for creating FlightGear Scenery from it. Added a 'geonameid' column for joining urban areas with GeoNames (see below). Current details explained here, will get merged some time.
  • VMap1: First attempt of a selection that would be "nice to have" for FlightGear - and certainly for other purpose as well. Added a 'geonameid' column for joining urban areas with GeoNames.
  • AptNav: Geometric average of runway center locations as used by the FlightGear and X-Plane flight simulators; data taken from here. Locations converted to OGC-style POINT geometries. Use 'icao' column for searching.
  • GSHHS: GSHHS 1.3 shorelines.
  • SWBD: SRTM2 Water Body Data.
  • MGRS: Military Grid Reference System, alias UTMREF.
  • TIGER: TIGER line data - currently an overview that shows only major roads; to be completed (thanks to Chris Holmes at The Open Planning Project).
  • GeoNames: Complete content of the "allCountries" export table from the NGA GEOnet Names Server. Locations converted to OGC-style POINT geometries.
  • FGSODB: Complete dump of the FlightGear Scenery Objects Database; models consist of AC3D geometries, RGB textures and in some cases animations that are defined in XML files. Locations converted to OGC-style POINT geometries.

• TODO
  • Generation of per-country and per-region shapefiles; distribution via HTTP and via geotorrents.org

Old status

• see Geodata processing at telascience.org#Data:_VMAP0_1:1Mio_World_Vector_Data

Blue Marble NG

• Mapserver as WMS

Landsat-7

• Mapserver as WMS
• Telascience already serving the raw data - http://onearth.telascience.org/

Status

• Waiting for disk space to finish unpacking the raw data on zuluviz.sdsu.edu
• Interim plan is to write a simple WMS wrapper script that generates a GDAL VRT to assemble composites on the fly

Metadata

• Geodata Metadata Requirements - a baseline for what would be asked for / expected of data sets in an OSGeo repository
• A simple metadata-in-GeoRSS webservice that is also as FGDC compliant as possible/desirable.
• Simple Catalog Interface

See Also

• Geodata Discovery Working Group - half-dormant
• MapDex offers a metadata search facility
• GeoNames is a gazetteer and naming collection
• http://www.fao.org/geonetwork/srv/en/main.search
• http://geoportail-geoportal.ainc-inac.gc.ca/metaindex_e.asp