Unidata Outreach Accomplishments and Challenges

Ben Domenico, March 2011

Relationship to Unidata 2013 Proposal

This work relates to several of the proposal goals: 1. Broadening participation and expanding community services; 2. Advancing data services
3. Developing and deploying useful tools; 5. Providing leadership in cyberinfrastructure. 

As noted in the two following sections,  the work was called out specifically in an interaction with the review panel and in the review panel summary.

Review panel question and UPC response

1e. Is the UPC prepared to provide the same quality of support to the newly engaged communities as it provides to its current constituents?

While the support for all users will remain at a very high level, that does not mean it will be exactly the same.   For example, for the core community Unidata provides comprehensive support for a full suite of tools from data services, through decoders, to complete analysis and display packages.  For  other cases, the tools that are specialized to their community may not be available via and supported by the UPC.  One example of this is the community of users of GIS tools.  In that case Unidata supports standards-based web services that make our datasets available in such a way that tools that incorporate those standard interfaces can avail themselves of  Unidata datasets.  Thus these new communities can continue to make use of the analysis and display tools they are familiar with while taking advantage of the data services of the traditional Unidata community. 

Excerpt from the proposal review panel report

Advocacy for Community Standards:  "In particular, the UPC could play a significant leadership role within committees and consortiums like OGC seeking to address the need to develop standards and technologies for data discovery. Unidata leadership and advocacy in this area could facilitate expanded utilization of Unidata information resources for other research areas like climate and provide Unidata users with easier access to other data sources like NASA satellite information. However, the OGC letter of recommendation in the proposal and the Unidata responses to the review panel questions regarding cyberinfrastructure did demonstrate that the Unidata was actively involved in community discussion of interface and data standards."

Summary of Recent Progress

Background on netCDF and CF formal standards efforts

Following on the success of Russ Rew and the netCDF team in establishing netCDF and CF as NASA standards, efforts continue to have CF-netCDF recognized internationally by the  Opengeospatial Consortium (OGC) as standards for encoding georeferenced data in binary form.

As the official UCAR representative to the OGC Technical Committee, Unidata participates in 3-4 technical committee meetings per year to ensure that Unidata and UCAR needs are met in the emerging international standards.

The overall plan and status is maintainted at  http://sites.google.com/site/galeonteam/Home/plan-for-cf-netcdf-encoding-standard.  In keeping with the proposal and review panel recommendations, the goal of this effort is to encourage broader use of Unidata's data by fostering greater interoperability among clients and servers interchanging data in binary form.  Establishing CF-netCDF as an OGC standard for binary encoding will make it possible to incorporate standard delivery of data in binary form via several OGC protocols, e.g., Web Coverage Service (WCS), Web Feature Service (WFS), and Sensor Observation Service (SOS).  For over a year, the OGC WCS SWG is already developing an extension to the core WCS for delivery of data encoded in CF-netCDF.  This independent CF-netCDF standards effort is complementary to that in WCS and hopefully will facilitate similar extensions for other standard protocols.

Progress on OGC standardization

In January 2011, the OGC Technical Committee voted to adopt the netCDF Classic as an official OGC binary encoding standard.  As of the writing of this report, the final standard specifications are being formatted for final publications, but the draft standards are still available in three documents: an overview primer, the core standard spec, and the binarry encoding spec.


Ongoing Outreach Activities

AccessData (formerly DLESE Data Services) Workshops 

The overall AccessData program is described at:  http://serc.carleton.edu/usingdata/accessdata/ and the most recent workshop page is: http://serc.carleton.edu/usingdata/accessdata/impacts/index.html.   The AccessData team is now working on several publications to document the results of the project.

Data Discovery Initiatives

In keeping with the Unidata 2013 Proposal review panel recommendation relating to collaborating with others to enhance the available data discovery facilities, the UPC and the Unidata community are following up on earlier collaborations with George Mason University and NASA.  The most recent work is with the U of Florence ESSI Labs team to use their tools to harvest search metadata from THREDDS data servers which can provide special challenges because of the size and volatility of their holdings. A new release of the ESSI Labs GI-cat package has addressed limitation of earlier versions which ran into difficulty with the Unidata Motherlode THREDDS server.  Members of our community are finding this tool useful enough that Rich Signell has created a YouTube video on "How to Configure GI-CAT for the first time": http://youtu.be/28biJHTQSrM
Work continues in our ongoing efforts to coordinate our data discovery and access systems with those of the hydrology community.  The most recent undertaking was described in an invited paper with David Maidment as the lead author at the Fall  2010 AGU:

Hydrologic information science requires several different kinds of information: GIS coverages of water features of the land surface and subsurface; time series of observations of streamflow, water quality, groundwater levels and climate; and space-time arrays of weather, climate and remotely sensed information. Increasingly, such information is being published as web services, in standardized data structures that transmit smoothly through the internet. A large "Digital Divide" exists between the world of discrete spatial objects in GIS and associated time series, and the world of continuous space-time arrays as is used weather and climate science. In order to cross this divide, it should be possible to search for quantities such as “precipitation” and to find the information no matter whether it comprises time series of precipitation at gage sites, or space-time arrays of precipitation from Nexrad radar rainfall measurements. This means that servers of discrete space-time hydrologic data, such as the CUAHSI HydroServer, and servers of continuous space-time weather and climate data, such as the Unidata THREDDS server, should be able to be indexed in a unified manner that will permit discovery of common information types across different classes of information services. This paper will explore options for accomplishing this goal using the CUAHSI HydroServer and the Unidata THREDDS server as representative examples of information service providers. Among the options to be explored is GI-cat, a federated, standards-based catalog service developed at the Earth and Space Science Informatics Laboratory of the University of Florence.

Some of these efforts are described in the August Unidata E-letter: http://www.unidata.ucar.edu/newsletter/2010aug/index.html#Article1

Other Collaborations:

  • NCAR GIS Program (official program of NCAR as of this year)
  • Marine Metadata Interoperability Project Steering Team
  • IOOS DMAC Steering Team
  • CUAHSI Standing Committee
  • UCAR wide representative to OGC Technical Committee
  • AGU ESSI Focus Group Board
  • ESIN Journal Editorial Board
  • Host for OGC Technical Committee Meeting September 2011
  • Liaison to OOI Cyberinfrastructure Project
  • Possible collaboration with UCSD on a follow on NSF proposal for the Marine Metadata Interoperability (MMI) project.

Planned Activities

At the April EGU, there will be a presentation on the status and plans for the CF-netCDF standardization effort.   A concise summary is given on the Goolge sites GALEON wiki


In the updated plan, the next steps will be standardization of the CF conventions, in particular those associated with gridded and point (discrete sampling) data types.  At the most recent OGC TC meeting, the CF-netCDF SWG strongly recommended consideration of the OGC Fast Track process for the CF conventions specification as well as for the netCDF4 binary encoding spec (which is actually based on a subset of HDF5 format).  At this point, it appears that a case could be made for a Fast Track approach for the CF conventions based on the already adopted NASA standard.   

The OGC Fast Track process is described in

There is also a pending NASA standard for the NetCDF4/HDF5 encoding

The netCDF enhanced data model will be an additional undertaking as an OGC extension to the core netCDF classic data model standard, but that will not come under the Fast Track process.

Relevant Metrics

The list of "other collaborations above includes ten organizations we have regular interactions with.  In most cases, our interactions are as representatives of our community on their steering or policy groups, so we have at least some voice in their direction.

The first three netCDF standards documents were adopted by the OGC technical committee with no comments and no dissenting votes.  I suppose that's sort of a negative metric in terms of counting but positive in terms of outcome.

Over the years of these standardization efforts, ESRI has incorporated the netCDF among the input and output formats that their arcGIS tools work with directly.  This represents a user community that numbers in the millions, but it isn't possible for us to measure how many of those users now use it to access our data.

The standards efforts enable us to collaborate on an ongoing basis with dozens of international organizations -- especially those represented in the OGC MetOceans, Earth System Science, and Hydrology Domain Working Groups.