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?