1. Crossing the Digital Divide
CUAHSI
Crossing the Digital Divide
Presented by: Fernando R. Salas
David Maidment, Enrico Boldrini, Ben Domenico, Stefano Nativi
CUAHSI Conference on Hydrologic Data and Information Systems Logan, Utah
April 22, 2011

2. Introduction and Motivation
Source: Iowa State University Department of Natural Resource Ecology and Management

3. Searching for Climate Data

4. What is the Digital Divide?
Observations and Time Series
Climate Observations and Grids
Remote Sensing
Geographic Information Systems (GIS)

5. Interoperability Challenges
Observations Data
Gridded Data
Measures variables over a discrete space-time domain
Stored in tables, relational databases and geodatabases
Measures variables over a continuous space-time domain
Stored in large multi-dimensional arrays in specialized formats
How can we connect these very different worlds together?

6. Hydrologic Information Systems

7. Observations Data Information Model
Data Source
United States Geological Survey (USGS)
Network
National Water Information System – Unit Values
Sites
Colorado River at Austin
Variables
Streamflow
Values
2,500 cfs at 8:30 am on
June 19th, 2011
Conceptually, we describe hydrologic observations data with a Point Observations Information Model.

8. Gridded Data Information Model
Data Source
National Climatic Data Center (NCDC)
Dataset
North American Regional Reanalysis (NARR)
Grid Size
32 kilometer
Variables
Temperature
Values
78 deg. Fahrenheit
at 8:00 am on
June 15th, 2000
Time 1
NARR

9. Data Cube Time {t} Time {t} Space {x,y} Space {x,y,z} Variable {vi}

10. THREDDS Data Servers
WCS
NetCDF
HTTP
OpenDAP
WMS

11. Distributed File Sharing Systems
Enables users to access large quantities of gridded data using standardized data services
Source:

12. Building a Series Catalog for Observations Data
Datacart – a collection of data series organized thematically
Observations Metadata Catalog
Source
Site Name
Location (Lat/Long)
Variable Name
Variable Units
Concept
Start Date
End Date
WaterML URI
WFS

13. Building a Series Catalog for Gridded Data
Datacart – a collection of data series organized thematically
Observations Metadata Catalog
Source
Coverage Name
Location (Lat/Long Box)
Variable Name
Variable Units
Concept
Start Date
End Date
WCS URI
WFS

14. Building a Catalog of Services
CSW
Time Series
Raster Series
WFS
WFS
CSW implemented all over!
HydroServers
WaterML
NetCDF
THREDDS Servers

15. Services Stack Framework
Catalog
Metadata
Data
Services
CSW
WFS
SOS
WCS
Catalog Services for the Web (CSW) enable metadata services describing observations data to be registered in a catalog of services.
Web Feature Services (WFS) enable data services to be completely described by metadata in a series catalog.
Sensor Observation Services (SOS) and Web Coverage Services (WCS) enable observations and climate data to be conveyed through the internet in a standardized manner.

16. Services Stack Framework for Observations Data
Catalog
Metadata
Data
Services
CSW
WFS
SOS
Catalog Services for the Web (CSW) enable metadata services describing observations data to be registered in a catalog of services.
Web Feature Services (WFS) enable observations data services to be completely described by metadata in a series catalog.
Sensor Observation Services (SOS) enable observations data to conveyed through the internet in a standardized manner.

17. Services Stack Framework for Gridded Data
Catalog
Metadata
Data
Services
CSW
WFS
WCS
Catalog Services for the Web (CSW) enable metadata services describing gridded data to be registered in a catalog of services.
Web Feature Services (WFS) enable gridded data services to be completely described by metadata in a series catalog.
Web Coverage Services (WCS) enable gridded data to conveyed through the internet in a standardized manner.

18. One Common Ontology CUAHSI Ontology Precipitation Precip Rainfall Rain
Streamflow
Turbidity
Snow
Cloud Cover
Precip
Rainfall
Rain
Total Precip
Precip
Rainfall
Rain
Total Precip
CUAHSI
Ontology

19. HydroPortal – A Catalog Service
Geoportal Extension of ArcGIS implements Catalog Services for the Web (CSW)
…enables data discovery across multiple data sources and types…

20. GI-cat Service Broker
GI-cat broker catalog mediation/adaptation solution
Standard based solution
Support to several international and community standards, including THREDDS, WCS, WFS, CSW.
Support to several standard discovery interfaces, including CSW AP ISO, OpenSearch
Successful harvesting of more than 400,000 resources
Courtesy of Enrico Boldrini from the
Earth and Space Science Informatics Lab

21. A SOA Broker/Mediator component
Service
Registry
Publish 
Find 
Service
Consumer
Client
Harvest
Service
Provider 
Bind
Order 
Bind 
Server
Protocol sharing
Service
Broker
Courtesy of Enrico Boldrini from the
Earth and Space Science Informatics Lab
Mediator

22. GI-cat Broker/Mediation component
Service
Providers
Registry
Processing capability
Service
Consumer
Client
OpenModeller
WPS
Local Repository /Cache
INSPIRE
portal
Harvest
Discovery capability
CSW-Core
CSW ISO
GeoNetwork CSW client
GI-cat
Service Broker / Mediator
OpenSearch
CSW ebRIM
CSW/ebRIM-EO
GBIF
ArcGIS Explorer
CSW client
CSW-ISO
Inventory capability
Functions:
Mediation
Distribution
Messaging
Persistence
Access
.....
THREDDS/OPeNDAP
GEO portal
CDI
WCS
WMS
WFS
ESA-HMA portal
CSW-EBRIM
CIM/EO
Access capability
WCS
WFS
WMS
Web browser
THREDDS/OPeNDAP
GBIF
OpenSearch
Mediator
Courtesy of Enrico Boldrini from the
Earth and Space Science Informatics Lab
Server

23. Interoperability Enabled by Standard Web Services
Data Services
Catalog Services
HydroServers
CSW
CSW
THREDDS Servers
HydroCatalog

24. Integrated Search

25. Hydrometeorologic Information System
HydroCatalog
HydroDesktop
HydroServer
WFS
CSW
SOS
WCS

26. Conclusions
Data access through web services can mask the variations in data structure between relational databases and data file systems

27. Questions?