Unidata Outreach Progress

Ben Domenico, October 2010

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."

Brief 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. 

Progress on OGC standardization

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. Recently, the OGC issued a press release announcing three initial documents in the standardization process: an overview primer, the core standard spec, and the binarry encoding spec.


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.   

After the public comment period and response to the comments, the updated CF-netCDF standards document will be voted on by the OGC Technical Committee as a whole.  A positive vote by a majority of the active OGC member organizations would establish CF-netCDF as a formal OGC standard

September 2010 OGC Technical Committee Meeting Highlights

Below is the powerpoint summary of the CF-netCDF Standards Working Group session at last week's OpenGeospatial Consortium Technical Committee meeting.   The session was held Tuesday, 21 September 2010   11:00 – 13:00
  • One (positive) comment so far from the RFC on the Core and Binary Encoding CF-netCDF Candidate Standards
  • Note that CF governing committee has been contacted regarding  CF submission to OGC, modeled on NASA SPG spec (Ben Domenico)
  • Description of the CF extension to the netCDF core (Stefano Nativi)  
  • Description of the CF-netCDF encoding extension to WCS (Stefano)
  • General Discussion
  • No motions, no votes
The resulting SWG action items were:
  • Follow up on suggestion to standardize vocabulary for some netCDF global variables.
  • Investigate sending a copy of OGC CF-netCDF RFC to the CF-conventions mail list
  • Check with HDF group to see if they are considering OGC standardization
  • Investigate which version of CF addresses CRS/Datum issues
  • Get the version numbers correct for all the standards being proposed and referenced in the CF-netCDF specs.
  • Get OPeNDAP community input on mechanism proposed to deliver OPeNDAP URL as a proxy for a netCDF file
One other topic of special interest that came up at the meeting is the fact that the stars are aligning for a couple meetings in Colorado a year from now.  UCAR/Unidata is hosting the OGC Technical Committee meetings the week of September 19, 2011 in Boulder and the FOSS4G (Free and Open Source 4 Geosciences) meetings and workshops are the week before (Sept 12) in Denver.  Both these meetings are of interest to many members of the community and we have people involved in planning for both.  In addition, we could plan for a special presence at either or both meetings or possibly could plan a "bridge" meeting/workshop of some sort between the two.

Ongoing Outreach Activities

AccessData (formerly DLESE Data Services) Workshops 

Unidata actively participated in this year's workshop in early February  at Colorado College in Colorado Springs. The overall AccessData program is described at:  http://serc.carleton.edu/usingdata/accessdata/ and this year's workshop page is: http://serc.carleton.edu/usingdata/accessdata/impacts/index.html.  We also hosted an AccessData PIs meeting at the UPC in August to plan the writing publications describing the results of the project.

Spanning the Digital Divide

David Maidment has sparked a new initiative in our ongoing efforts to coordinate our data systems with those of the hydrology community.  He describes it in an abstract for an invited paper at the Fall 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.

Thus far, the Unidata has been working 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.

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
  • OGC Oceans Interoperability Experiment sponsor
  • UCAR wide representative to OGC Technical Committee
  • AGU ESSI Focus Group Secretary
  • ESIN Journal Editorial Board
  • FOSS4G, Free and Open Source Software for Geosciences
  • Liaison to OOI Cyberinfrastructure Project
  • Possible collaboration with UCSD on a follow on NSF proposal for the Marine Metadata Interoperability (MMI) project.

Next Steps

The main items for the next several months are closing out the AccessData project with the summary publication, completing the OGC CF-netCDF standardization process (hopefully by the end of the year) and developing demonstrations of the viability of the standard working with the OGC, the hydrology community and the NCAR GIS program..  A roadmap for the OGC CF-netCDF SWG is at: http://portal.opengeospatial.org/files/?artifact_id=37335