Interoperability Day Introduction
Standards-based Web Services Interfaces toExisting Atmospheric/Oceanographic Data Systems
Ben DomenicoUnidata Program Center*
Unidata OGC Interoperability Day September 2007
*supported by NSF
Acronym Glossary
• GALEON (Geo-interface for Air, Land, Environment, Oceans NetCDF)
• FES (Fluid Earth Sciences, mainly the data systems of the atmospheric and ocean sciences)
• http://www.unidata.ucar.edu/content/publications/acronyms/glossary.html
Taking Advantage of Web Services for Data System Interoperability
GIS ClientGIS Client Applications Applications
FES ClientFES Client Applications Applications
OpenGIS Protocols:WCS, WFS, SOS, GML, CSW
OGC or proprietary GIS
protocols
OGC or OPeNDAPTHREDDS, ADDE.
FTP…protocols
GIS ServerGIS Server
GIS ServersGIS Servers
Demographic, infrastructure, Demographic, infrastructure, societal impacts, … societal impacts, …
datasetsdatasets
THREDDS ServerTHREDDS Server
FES ServersFES Servers
Station obs, satellite, radar, Station obs, satellite, radar, forecast model output, … forecast model output, …
datasetsdatasets
GALEON (Geo-interface for Air, Land, Earth, Oceans NetCDF)
• Foster interoperability between data systems of FES and GIS communities
• Provide standard interfaces, e.g.,– Web Coverage Service (WCS)– Web Feature Service (WFS)– Sensor Web Enablement (SWE)– Catalog Services for the Web (CSW)
• To existing netCDF/THREDDS services, e.g.,– HTTP access to netCDF– OPeNDAP client/server protocol– THREDDS catalogs
NetCDF/OPeNDAP NetCDF/OPeNDAP data serverdata server
WCS Client
…
THREDDS THREDDS catalogs catalogs
enhanced with enhanced with NcML-GMLNcML-GML
WCS capabilities
THREDDS interface
WCS description
THREDDS interface
OPeNDAP
NetCDF dataset
NetCDF
OPeNDAP
GMLgenerator
geoTIFFgenerator
WCS coverage
netCDFgeoTIFF
NcMLGMLgetCoverage
getCapabilities
describeCoverage
THREDDS enhanced catalog generation tools
THREDDS catalogsNcML-G metadata
netCDF objects
ADDE
ADDE
CS-W Client
Phase 2 Issues
1. Is WCS 1.1 adequate for serving netCDF datasets such as those on the servers at Unidata, the University of Florence, George Mason University, NERC, NCDC, and the PFEL, and others?
2. In the context of serving traditional netCDF datasets, what's the relationship between WCS and other standard specifications?
WCS for Other Dataset Types
• GALEON 1 focus on “5D” forecast model output
• For GALEON 2?– point or "station" observations– vertical profile and trajectory datasets– swath data from polar orbiting satellites – radial data from radar stations
General Dataset Categoriesfrom RAL “features workshop”
Unidata CDM:
Gridded datasets
Collections of “station observations”
Vertical profile and trajectory datasets
Swath data from polar orbiting satellites
Radial data from ground-based radar stations
CSML Scientific Features
GRID
Profile
Ragged section
Scanning radar
Profile series
OGC SWE Sampling Feature Classes
A Station samples the world at a point,
a Profile along a curve,
a SurfaceOfInterest on a surface,
and a SolidOfInterest in a solid region.
Grids and Station Observations
WCS and other OGC Specs
• Need standards-based catalogs for collections of datasets (CSW-ebRIM?)
• Relationship between CSW and getCapabilities lists
• Collections of point time series data (WCS, WFS, or SOS)
• GML dialects– ncML-GML– CSML– GMLJP2
SOS
WCS
CF-netCDFCoverages
WCSWFSWCS
WFS
WC
S
WFS
WFS/ WCS ClientWCS/WFS Server
CSML Sampling Features delivered as
CF-netCDF Coverages
WCS
WCS ClientWCS/WFS Server
WFS
WC
S
CF-netCDFCoverages
ncML-GML Sampling Featuresdelivered as
CF-netCDF Coverages
THREDDSWCS Server
ObservationDatasets
Model OutputDatasetsObserving System Unidata Internet Data
Distribution System
WCS
CF-netCDFCoverages
Sensor Observation Service
SOS
Clients
WCS, WFS, SOS, CS-W Clients
SOS
WCS
CF-netCDFCoverages
WCSWFSWCS
WFS
WC
S
WFS
WFS/ WCS ClientWCS/WFS Server
CSML Sampling Features delivered as
CF-netCDF Coverages
WCS
WCS ClientWCS/WFS Server
WFS
WC
S
CF-netCDFCoverages
ncML-GML Sampling Featuresdelivered as
CF-netCDF Coverages
THREDDSWCS Server
ObservationDatasets
Model OutputDatasetsObserving System Unidata Internet Data
Distribution System
WCS
CF-netCDFCoverages
Sensor Observation Service
SOS
CS-Wdiscovery
for allresources
Questions for Participants
• What’s the right mix and architecture of standards-based web services?
• Is there anything your organization can contribute in the next six months to a year?– clients– servers– testing
• To get your part done, what’s needed from others?
For More Information
• OGC documents:http://portal.opengeospatial.org/index.php?m=projects&a=view&project_id=173
• Status of implementations and interoperability tests:http://galeon-wcs.jot.com/WikiHome
References
• netCDFhttp://my.unidata.ucar.edu/content/software/netcdf/index.html
• GALEONhttp://my.unidata.ucar.edu/content/projects/THREDDS/GALEON/GALEON-Activity-Plan.htm
• Acronym Glossaryhttp://my.unidata.ucar.edu/content/publications/acronyms/glossary.html
