Open Source GI and Cartography Georg Gartner TU Wien Outline • 1. Introduction • 2. Free and Open Source Software for GI and cartography • 3. Open standards and technologies for GI and Cartography • 4. Open Software for GI and Cartography • 5. Case studies in urban planning 1. What is Free and Open Source Software? • Four essential freedoms1: – The freedom to run the program, for any purpose (Freedom 0) – The freedom to study how the program works, and change it to make it do what you wish (Freedom 1) – The freedom to redistribute copies so you can help your neighbor (Freedom 2) – The freedom to distribute copies of your modified versions to others (Freedom 3) – Access to the source code is a precondition for Freedom 1 and 3. • A program is free software if users have all of these freedoms. 1. http://www.gnu.org/philosophy/free-sw.html Definition • Free software is a matter of the user‘s freedom to run, copy, distribute, study, change and improve the software. • “Free software” is a mater of liberty, not price. – “free speech” vs. “free beer” • Google Maps (APIs) is free, but not a free software. Terms of Use • Bing Map? Not! Privacy and Legal 2. Free and Open Source Software for Geospatial • Open source GIS provides accessibility, low cost solutions and lowers the entry barriers for the use of geospatial technologies for all. • Relevant communities – Open Geospatial Consortium (OGC) – Open Source Geospatial Foundation (OSGeo) • Research communities: – ICA Working Group on Open Source Geospatial Technologies OGC • The Open Geospatial Consortium, Inc.® (OGC) is a non-profit, international, voluntary consensus standards organization that is leading the development of standards for geospatial and location based services. • Mission – To serve as a global forum for the collaboration of developers and users of spatial data products and services, and to advance the development of international standards for geospatial interoperability. OGC’s standards • Geography Markup Language – GML • Web Map Service (WMS) • Web Coverage Service (WCS) • Web Feature Service (WFS) • Location Services (OpenLS) • …. http://www.opengeospatial.org/standards OSGeo • The OSGeo is a not-for-profit organization whose mission is to support and promote the collaborative development of open geospatial technologies and data. • provides financial, organizational and legal support to the broader open source geospatial community. • Hosting the FOSS4G conferences (Free and Open Source Software for Geospatial) http://www.osgeo.org/content/foundation/about.html OSGeo’s Projects • Web Mapping – Deegree, Geomajas, GeoServer, Mapbender, MapBuilder, MapFish, MapGuide Open Source, MapServer, OpenLayers • Desktop Applications – GRASS GIS, OSSIM, Quantum GIS, gvSIG • Geospatial Libraries – FDO, GDAL/OGR, GEOS, GeoTools, MetaCRS, PostGIS • Metadata Catalog – GeoNetwork • Other Projects – Public Geospatial Data, Education and Curriculum ICA Working Group on Open Source Geospatial Technologies • The WG aims to promote multi-national holistic research in free and open source geospatial technologies in order to make accessible the latest developments in open source tools to the wider cartographic community. • The WG attempts to enhance the usage of free and open source geospatial tools among the cartographic community worldwide, especially for education. • A serial of conferences and workshops 3. Open standards and technologies • GML (current version 3.2.1) – an XML grammar for expressing geographical features – Used as an open interchange format for transmitting geographic data on the Internet – GML was adopted as an International Standard (ISO 19136:2007) in 2007. – Ordnance Survey of GB use GML as the (only) format for supply of MasterMap data1 1. http://www.ordnancesurvey.co.uk/oswebsite/xml/schema/index.html 3. Open standards and technologies • KML (Keyhole Markup Language ) – a language for the visualization of geographic information tailored for "Google Earth". – complements GML: KML can be used to carry GML content, and GML can be “styled” to KML for the purposes of presentation. • SVG (Scalable Vector Graphic, by W3C) – an XML-based file format for describing two- dimensional vector graphics, both static and dynamic – Can be used to visualize geospatial dataset (such as GML) 3. Open standards and technologies • OGC’s OpenGIS Web Services (OWS) – Web Map Service (WMS 1.3.0) • Provides georeferenced map images • Return data types: GIF, PNG, JPEG, etc. – Web Feature Service (WFS 1.1) • Provides vector data on demand • Return data types: GML 3.1.1, and GML 2.1.2 – Web Converage Service (WCS 1.1) • Provides raster data on demand • Return data types: GeoTIFF, DTED, HDF-EOS, or NITF. 3. Open standards and technologies • WMS, WFS and WCS are designed as server- side mapping methods. • Map (and other) requests are made through standard HTML methods1 – URL – Parameters supplied within URL (GET) or hidden in document (POST) – One request gives one response 1. http://www.sigte.udg.edu/summerschool2010/uploads/XMLandOWS.pdf A WMS Example (A large image (1000 x 1000 pixels) of several cryospheric parameters in a polar stereographic projection focused on the Arctic): http://nsidc.org/cgi-bin/atlas_north?service=WMS&version =1.1.1&request =GetMap&srs=EPSG:32661&format=image/gif&width=1000&height=1000&bbox=-2700000,- 2700000,6700000,6700000&layers=sea_ice_extent_01,land,snow_extent_01,permafrost_extent,country_ borders,treeline,north_pole_geographic,arctic_circle,country_labels,geographic_features_sea A WFS Example (Elevation contours for the Greenland ice sheet): http://nsidc.org/cgi- bin/atlas_north?service=WFS&version=1.1.0&request=GetFeature&typename=greenland_elevation_contours GML Rendering in QGIS A WCS Example (A GeoTIFF of sea ice concentration at 25-km resolution in a polar stereographic projection focused on the Arctic ) : http://nsidc.org/cgi-bin/atlas_north?service=WCS&version=1.1.1&request =GetCoverage&crs=EPSG:32661&format=GeoTIFF&resx=25000&resy=25000&bbox=-2700000,- 2700000,6700000,6700000&coverage=sea_ice_concentration_01 From: http://nsidc.org/data/atlas/ogc_services.html#WCS 3. Open standards and technologies • Web Processing Service – provides rules for standardizing how inputs and outputs (requests and responses) for geospatial processing services, such as polygon overlay. • Sensor Observation Service – provides an API for managing deployed sensors and retrieving sensor data and specifically “observation” data. • More standards …. – OGC: http://www.opengeospatial.org/standards – ISO TC 211: http://www.isotc211.org/ 3. Open standards and technologies • The above standards and technologies are adopted in many Open Source GI and Cartography applications. 4. Open Software for GI and Cartography • Different kinds of software – Web Mapping – Desktop Applications – Geospatial Libraries – Metadata Catalog – Others • We will introduce some typical software. 4.1 Web Mapping • Map Server (from OSGeo) – Originally developed at the University of Minnesota (UMN Map Server) – an open source development environment for building spatially- enabled web mapping applications and services. http://www.osgeo.org/mapserver 4.1 Web Mapping • OpenLayers – provides an JavaScript API for building rich web- based geographic applications similar to Google Maps and Bing Maps. 4.2 Desktop Applications • Quantum GIS (QGIS) – QGIS lets you browse, edit and create a variety of vector and raster formats, including ESRI shapefiles, spatial data in PostgreSQL/PostGIS, GRASS vectors and rasters, or GeoTiff. – supports different plugins 4.2 Desktop Applications • GRASS (Geographic Resources Analysis Support System) • For performing spatial analysis • consists of more than 350 modules for processing vector (2D/3D), raster and voxel data • can serve as a Desktop GIS and as the backbone of a complete GIS infrastructure. 4.3 Geospatial Libraries • GeoTools – an open source Java code library which provides standards compliant methods for the manipulation of geospatial data. – It implements OGC specifications (standards) as they are developed. 4.3 Geospatial Libraries • PostGIS – an open source software program that adds support for geographic objects to the PostgreSQL object-relational database. – follows the Simple Features for SQL specification (standard) from OGC. QGIS Displaying Vector Data from PostGIS 4.4 Metadata Catalog • GeoNetwork opensource – a catalog application to manage spatially referenced resources – providing powerful metadata editing and search functions as well as an embedded interactive web map viewer. 5. Case studies • SITEL (México) • a spatial data infrastructure, allows various government agencies to share data to be included in their own projects as health, security, urban furniture or mobility. • over 1,910 vectorial layers plus another 70+ raster files, provided through PostGIS and WMS/WFS/WCS services with Mapserver. • QGIS is used for data checking. Data Checking in Satellite imagery Orthophotos Digital elevation models QGIS http://postgis.refractions.net/documentation/casestudies/sitel/ 5. Case studies • Forestry planning (Basel, Switzerland)1 – QGIS is used to import of existing data, digitizing, Analysis, Print and export. Extract of the forestry measurements map 1. http://www.qgis.org/en/community/qgis-case-studies/basel-switzerland.html 5. Case studies • Examples of using GRASS – http://grass.osgeo.org/intro/index.php • Case studies of QGIS – http://qgis.osgeo.org/en/community/qgis-case- studies.html • ... Forschungsgruppe Kartographie Technologie „Push“ in der Kartographie