Interoperability Day Introduction
Standards-based Web Services Interfaces to
Existing Atmospheric/Oceanographic Data Systems
Ben Domenico
Unidata 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/public
ations/acronyms/glossary.html
Taking Advantage of Web Services for
Data System Interoperability
GIS Client
Applications
OGC or
proprietary GIS
protocols
FES Client
Applications
OpenGIS Protocols:
WCS, WFS, SOS, GML, CSW
GIS Servers
GIS Server
Demographic,
infrastructure,
GIS Server
societal impacts, …
datasets
OGC or OPeNDAP
THREDDS, ADDE.
FTP…protocols
FES Servers
THREDDS Server
THREDDS
Station obs, Server
satellite, radar,
forecast model output, …
datasets
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
CS-W Client
WCS Client
NcMLGML
getCapabilities
getCoverage
describeCoverage
WCS capabilities
WCS description
THREDDS interface
THREDDS interface
THREDDS catalogs
NcML-G metadata
THREDDS
catalogs
enhanced with
NcML-GML
NetCDF/OPeNDAP
data server
geoTIFF
netCDF
WCS coverage
GML
generator
geoTIFF
generator
ADDE
OPeNDAP
NetCDF
netCDF objects
ADDE
OPeNDAP
NetCDF dataset
THREDDS
enhanced catalog
generation tools
…
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 Categories
from 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
OGC SWE Sampling
Feature Classes
 GRID
 A Station samples the
world at a point,
 Profile
 a Profile along a
curve,
 Ragged section
 Scanning radar
 Profile series
 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
Clients
SOS
WFS
WCS WFS
WCS
Sensor Observation Service
WFS
SOS
WCS
WFS
CSML Sampling Features
delivered as
CF-netCDF Coverages
WFS/ WCS Client
WCS/WFS Server
ncML-GML Sampling Features
delivered as
CF-netCDF Coverages
CF-netCDF
Coverages
WCS Client
WCS/WFS Server
CF-netCDF
Coverages
CF-netCDF
Coverages
THREDDS
WCS Server
Observing System
Unidata Internet Data
Distribution System
Observation
Datasets
Model Output
Datasets
WCS, WFS, SOS, CS-W Clients
SOS
WFS
WCS WFS
WCS
Sensor Observation Service
WFS
SOS
WCS
WFS
CSML Sampling Features
delivered as
CF-netCDF Coverages
WFS/ WCS Client
WCS/WFS Server
ncML-GML Sampling Features
delivered as
CF-netCDF Coverages
CF-netCDF
Coverages
WCS Client
WCS/WFS Server
CS-W
discovery
for all
resources
CF-netCDF
Coverages
CF-netCDF
Coverages
THREDDS
WCS Server
Observing System
Unidata Internet Data
Distribution System
Observation
Datasets
Model Output
Datasets
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
• ben@unidata.ucar.edu
References
• netCDF
http://my.unidata.ucar.edu/content/softwar
e/netcdf/index.html
• GALEON
http://my.unidata.ucar.edu/content/projects
/THREDDS/GALEON/GALEON-ActivityPlan.htm
• Acronym Glossary
http://my.unidata.ucar.edu/content/publicati
ons/acronyms/glossary.html