EURO4M Project Kick-Off, April 2010
OGC Web Services
Data visualization using OGC web services
Maarten PliegerWim Som de Cerff
Royal Netherlands Meteorological Institute (KNMI)R&D Information and Observation Technology
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Introduction
Web Services from the Open Geospatial Consortium (OGC)
Web Map Service (WMS)
Web Coverage Service (WCS)
WMS/WCS portal and server (ADAGUC)
Styled layer descriptors (SLD)
GIS clients supporting WMS/WCS
Application of OGC services in EURO4M
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Introduction to OGC servicesOGC – Open Geospatial Consortium (www.opengeospatial.org)
currently ~400 organizations standards for geospatial content and servicesGIS data sharing and processing
Services used within the ADAGUC project:ADAGUC: Atmospheric Data Access for the Geospatial User Community, was finished in 2009)
Web Map Service (WMS) - for imagesWeb Feature Service (WFS) - for vector dataWeb Coverage Service (WCS) - for raster data
WMS is primarily for visualization
WFS and WCS are for retrieval of data, respectively features and coverages
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Web Map Service - WMSA WMS is used to generate visualizations of geospatial data in the form of 2D images suitable for transfer over the World Wide Web
2 metre temperature (K)
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Web Map Service - WMS
A WMS is able to re-project and transform geospatial data to other projections
Web Map Services from different sources can be combined to a single presentation
Original data stays at the source, WMS is purely a visualisation
Just images are transferred; network usage is relatively low(compared to transferring data files)
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WMS Servers Images WMS client
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WMS Requests - overview
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Web Coverage Service - WCSSimilar to WMS, but returns data instead of visualizations
Returns observations in a regular spaced gridProvides data in geotiff, ascii, netcdf, HDF5, etc…
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Developed for making the KNMI precipitation radar available in OGC services (March 2009)Maintained and extended during other projects
Features: WMS 1.0 and WMS 1.1.1 (visualization) WCS 1.0 (data)Supports Time dimension and real-time update of data Proj.4 projection strings in getmap requestsUses GDAL for WCS outputAnimated gifSupport for named Styles: bilinear interpolation and contouring/shadingSuitable for all raster ADAGUC files (NetCDF 3/4 with CF)
Uses PostgreSQL database to keep track of available dataConfigurable by XML files
Software for WMS and WCS: ADAGUC Server
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WMS GetCapabilities
WMS GetMap
WMS GetFeatureInfo
WMS GetLegendGraphic
Web Portal (from ADAGUC)
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ArcGIS ExplorerArcGIS Explorer Google EarthGoogle Earth Quantum GISQuantum GIS
gvSIGgvSIG ArcGIS DesktopArcGIS Desktop UDIGUDIG
IDVIDV
GIS clients supporting WMS and/or WCS
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Styling using Styled Layer Desriptors (SLD)
style=default
style=psl/bilinear
style=psl/shadedcontour
Styling of sea level pressure (psl) using customizable styles
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OGC services in other projects at the KNMI
Rheinblick Hyras interpolation projectInterpolated datasets are made available using OGC services
KNMI weatherstation web applicationUses the KNMI precipitation radar WMS
Meteosat Second Generation (MSG) KNMI productsWill be converted to the ADAGUC data format and made availabe in OGC services
IS-ENESClimate model data will be made available in OGC services (DEMO)
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Possible application of OGC services in EURO4MThe OGC services presented here are suited for:– Combination of Web Map Services from different sources– Retrieval of geospatial data in a GIS compatible format– Viewing maps interactively on a web page» Maybe part of a web climate bulletin?
Currently less suited for:– Final presentation in a climate bulletin paper » Use existing tools for final editing
“Ideal situation”– Each participant provides his data using OGC services– Data from all participants can be displayed and combined in a portal– Anybody is able to use data from these OGC services for his own
analysis and algorithms
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Possible data format for EURO4M: NetCDF4-CF•NetCDF4 with Climate and Forecast conventions (CF conventions)
– Standard names, standard units (http://cf-pcmdi.llnl.gov/documents/cf-standard-names/)
– Identify and compare data– Locate data in space–time as a function of other independent
coordinate variables (time, latitude and longitude):
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Questions and/or discussion?