CGNS Steering Committee

Telecon Minutes

The meeting was called to order at 2:00pm. There were 16 attendees, as listed below.

• Charter/Membership - Bob Bush indicated that he received a letter from ONERA indicating that they would like to be formal members of the Steering Committee. Marc Poinot attended the meeting and introduced himself and described ONERA's interest in the committee and their activities with CGNS. After some discussion, it was decided to introduce a formal motion at the Reno meeting to increase the number of Steering Committee members allowed by the Charter to 17, and to elect ONERA to serve on the Steering Committee.
  
  
• ISO Status - Ray Cosner was unavailable for the telecon. Bob Bush gave a quick summary of the status. There was a thorough review of the draft documents at the ISO meeting in Japan in September. The process is continuing more or less on schedule.
  
  
• Documentation - Charlie Towne gave the status of the CGNS documentation pages of the web site. NASA closed all external access to their web pages following the September 11 incidents. Charlie has completed the paperwork required to re-open the site, and expects the documents to be available soon. In the mean time, he has fielded several requests for copies of the documentation and sent information to individuals via e-mail.

  The documentation has been revised with clarifications to the Family_t sections.

  There has been no movement on the AIAA Standard. Charlie Towne will contact Jim French at the AIAA to see what the next steps should be. We are waiting for AIAA to request the documentation in the form they require.

  Charlie Towne received e-mail requesting to copy portions of the CGNS documentation to another site as reference material. As all CGNS information is considered in the public domain, and we encourage the widest use of the Standard, the Committee has no objections. However we strongly recommend that they instead provide links to the CGNS documentation so that the revisions are reflected at the referencing site, and the CGNS committees and contributors are be properly acknowledged.
  
  

• Reno Meeting - Dave Edwards reported that he has requested a room for 30-45 people for Monday evening of the Reno AIAA Aerospace Sciences Conference for the Steering Committee meeting, and a Users meeting. These will also be announced at the AIAA web site, and in the conference proceedings. We are tentatively scheduled for 7-8pm for the Steering Committee, and 8-9 for the User's meeting. Times will be finalized soon.

  A technical paper on the status of CGNS implementations in industry has been accepted. Dave Edwards is collecting input from various organizations on their status, and will be drafting the paper in November. He will send the paper out for review in December, and it will be presented at the Reno meeting. Anyone interested in having their organizations CGNS implementation status summarized in the paper is encouraged to submit contributions to Dave.
  
  

• Software Support - The sub-committee working on Object Oriented language access to CGNS files has been quite active. One of the questions that has come up is the relationship between CGNS and ADF. Currently, ADF is the only implementation of the SIDS. However, there are other database standards (e.g. HDF-5) that might provide more functionality that ADF (e.g. parallel access). The SIDS and the emerging ISO standard do not specify how the underlying data is actually stored, and would seem to permit implementations in addition to ADF. However, this would potentially destroy the data sharing capabilities, which is the major driver for CGNS implementations. If multiple implementations of the SIDS is allowed, it was felt that the mid-level library and other software supported by the committee should be able to detect and read all of the allowed implementations, without user intervention. A definition of what constitutes a `CGNS file' is needed that spells out our position on what constitutes a CGNS file, and what the committee will support. Chris Rumsey will draft a policy statement on data base implementations of CGNS. Bob Bush, Manuel Kessler and Marc Poinot will review the draft, and the full committee will review the final statement. We hope to adopt a formal position that will be published on the Web site at the Reno meeting.

  There was some discussion of the current C++ implementation being done by Manuel Kessler and Udo Tremel, and if it represents a data access mechanism, or includes enough functionality that it should also be considered a utility that operates on the data.

  The chemistry extension is being re-worked somewhat to conform to new inputs by chemistry experts. It is hoped that the revision will be complete soon, and implementation completed (by Intelligent Light) by the end of January.

  The link and user defined data extensions are being implemented by Intelligent Light, and should be available by the end of January.

  Diane Poirier has implemented a CVS based version control system for the libraries. Intelligent Light is using this system to implement the extensions and serving as an alpha test for remote updates to the code.
  
  

• Issues - Doug McCarthy drafted a policy that would allow, encourage or enforce dues from the Steering Committee to be used to fund support activities. There was discussion on the feasibility of enforcing the policy, and other potential funding mechanisms. It was felt that proposals for specific extensions to the software were generally easier to justify funding. We will continue to discuss the issue as we move forward.

  The next meeting is scheduled for Reno in January. Bob Bush (or anyone else who would like to suggest) will determine if there is a need for a telecon in December to prepare for the meeting.

The meeting was adjourned at about 3:30.

Attendees