Extending GDAL/OGR and UMN MapServer

Transcription

1 Extending GDAL/OGR and UMN MapServer Maarten Plieger Nils de Reus Providing the building blocks for a geospatial infrastructure This project is sponsored by Space for Geo-Information

2 Introduction Overview on the datasets UMN MapServer and GDAL / OGR Extending the GDAL driver Extending the OGR driver Patching UMN MapServer ADAGUC Web Portal This project is sponsored by Space for Geo-Information

3 Instruments AMSR GOME Datasets Sciamachy Datasets Soil Moisture FRESCO NO 2, CH 4, CO, O 3 GOME O 3 in ArcGIS Explorer - using WMS Goal: Provide data through OGC Services

4 Datasets -> GIS DATA PRODUCTS SERVICES SCIAMACHY GOME MSG radar AMSR-E Binary Binary Binary Binary Binary ASCII Binary Binary Other ADAGUC Container ADAGUC Format Container ADAGUC Format Container Format GDAL/OGR WMS WFS WCS WWW IExplorer ArcGIS gvsig udig GoogleEarth & many others

5 UMN MapServer and GDAL/OGR UMN MapServer Developed by the University of Minnesota (UMN) Supports WMS, WFS, WCS, WMC, Filter Encoding, SLD, GML, SOS Data can be accessed using GDAL/OGR Fast renderer Geospatial Data Abstraction Library (GDAL) Raster datasets; over 70 formats supported Used by many software products: ESRI ArcGIS, GRASS, OpenEV, Quantum GIS Used in UMN Mapserver for raster access OGR Simple Features Library Vector datasets; over 20 formats supported ESRI Shapefiles, PostGIS, Oracle Spatial Used in UMN Mapserver for vector access Part of the GDAL library

6 Services with UMN MapServer ADAGUC Raster Files Images PNG GIF JPEG GDAL WMS extended UMN MapServer WFS Vector GML2 GML3 ADAGUC Vector Files OGR WCS Raster ADAGUC AAIGrid GeoTiff Etc..

7 GDAL ADAGUC Raster driver Based on existing NetCDF3 driver from Denis Nadeau and Frank Warmerdam Convert between ADAGUC files and formats supported by GDAL Uses NetCDF4/HD5 and UDUNITS libraries Climate and Forecast 1.2 conventions Features the ADAGUC metadata model Metadata is copied and updated where needed Additional metadata can be supplied using an NCML file For backwards compatibility: NetCDF3 output The driver is available from the OSGEO wiki on

8 GDAL: Variables and time gdalinfo file.nc gdalinfo ADAGUC:file.nc:TMTNO2 gdalinfo ADAGUC:file.nc:TMTNO2:time=10 gdal_translate of AAIGRID ADAGUC:file.nc:TMTNO2:time=10 out.asc

9 OGR ADAGUC Vector driver Reads the ADAGUC vector format Convert ADAGUC to ESRI shapefiles: ogr2ogr -f "ESRI Shapefile" out.shp adagucinputfile.nc ADAGUC files can not be created from OGR formats: The ADAGUC format expects four vertices for each tile Most vector files contain polygons with lots of vertices The driver is available from the OSGEO wiki on

10 UMN MapServer Supports WMS and WCS time Although not supported by most GIS clients Very active and helpfull mailing list Questions and problems are usually answered within the hour High performance One of the fastest renderers A few minor issues solved Filenames with a : in the filename were incorrectly interpreted when using WCS Metadata needed by GDAL was not passed by UMN MapServer Patches will be submitted on the UMN MapServer site Current issues Currently no information can be queried about a certain location when using WMS Time This will be solved by the developers soon

11 Features: ADAGUC Web Portal Combining services from different institutes KNMI and VU data are accessible in the same portal Overlay layers from different services WMS Time support For compatibility with other clients used as little as possible GetFeatureInfo Support for Legends Map Resizing WCS or WFS access where applicable Direct access to the original ADAGUC files Used techniques: HTML, CSS, XML, PHP, JSON, AJAX and JavaScript Uses JavaScript libraries ExtJS WebmapJS Custom made

12 ADAGUC Web Portal WMS GetMap WMS GetLegendGraphic WMS GetCapabilities WMS GetFeatureInfo

13 Download data from the Portal Download the original file, or convert to your favorite GIS format using OpenGIS Download the original file Raster files are downloaded using WCS Vector files are downloaded using WFS Depending on the datatype, which service is needed? The right service is automatically selected WCS DescribeCoverage WFS MetadataURL WFS or WCS?

14 Select Bounding Box WFS Service Viewing window or Custom bounding box? Only GML available as output format Researching the possibility to export directly into ESRI shapefiles

15 Optimal parameters are automatically set Select a Bounding Box native bounding box view window custom? Resolution Use width and height or resx and resy? Support for WCS time Choose your favorite GIS format WCS Service Parameters derived from DescribeCoverage

16 GDAL ADAGUC driver Open Issues Supports currently only the dimensions lat, lon and time Support for other dimensions like height can be added OGR ADAGUC driver Reads the whole source NetCDF file in to memory Should only read the parts that are needed UMN MapServer WMS GetFeatureInfo does not yet return data when querying on time layers Support for x and y (2D) data is easy Support for x, y, time and height is tricky Not many GIS clients out there that support WMS time

17 Summary ADAGUC NetCDF4 used with GDAL/OGR and UMN MapServer Web Portal communicates with the server using purely OpenGIS services Third parties can setup their own services using the building blocks created within the ADAGUC project The demonstrated atmospheric datasets are now very well accessible to GIS users!

18 Questions?