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OGC Web Services. Data visualization using OGC web services Maarten Plieger Wim Som de Cerff Royal Netherlands Meteorological Institute (KNMI) R&D Information and Observation Technology. Introduction. Web Services from the Open Geospatial Consortium (OGC) Web Map Service (WMS)
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OGC Web Services Data visualization using OGC web services Maarten Plieger Wim Som de Cerff Royal Netherlands Meteorological Institute (KNMI) R&D Information and Observation Technology
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
Introduction to OGC services OGC – Open Geospatial Consortium (www.opengeospatial.org) currently ~400 organizations standards for geospatial content and services GIS 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 images Web Feature Service (WFS) - for vector data Web Coverage Service (WCS) - for raster data WMS is primarily for visualization WFS and WCS are for retrieval of data, respectively features and coverages
Web Map Service - WMS A 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)
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)
Web Coverage Service - WCS Similar to WMS, but returns data instead of visualizations Returns observations in a regular spaced grid Provides data in geotiff, ascii, netcdf, HDF5, etc…
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 requests Uses GDAL for WCS output Animated gif Support for named Styles: bilinear interpolation and contouring/shading Suitable for all raster ADAGUC files (NetCDF 3/4 with CF) Uses PostgreSQL database to keep track of available data Configurable by XML files Software for WMS and WCS: ADAGUC Server
Web Portal (from ADAGUC) WMS GetMap WMS GetLegendGraphic WMS GetCapabilities WMS GetFeatureInfo
GIS clients supporting WMS and/or WCS ArcGIS Explorer Google Earth Quantum GIS gvSIG ArcGIS Desktop UDIG IDV
Styling using Styled Layer Desriptors (SLD) Styling of sea level pressure (psl) using customizable styles style=default style=psl/bilinear style=psl/shadedcontour
OGC services in other projects at the KNMI Rheinblick Hyras interpolation project Interpolated datasets are made available using OGC services KNMI weatherstation web application Uses the KNMI precipitation radar WMS Meteosat Second Generation (MSG) KNMI products Will be converted to the ADAGUC data format and made availabe in OGC services IS-ENES Climate model data will be made available in OGC services (DEMO)
Possible application of OGC services in EURO4M The 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
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):