2006-09-28: GALEON Phase II

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Title: GALEON Phase II
Date: 2006/9/28
For User: Rhusar
Status: InProgress
About Project or Tool: {{{about}}} (Add New project or tool)
Objective: [[:{{{Objective}}}]] (Add New Objective)

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During the last several weeks at the Unidata User Workshop, the ESIP Federabion meeting, and at IGARSS 2006, I had the opportunity to discuss possible objectives for the GALEON Phase 2 Interoperability Experiment with a number of GALEON paricipants. From what I can decipher from my cryptic notes, the goals can be divided into 3 categories:

1. Implement and test clients and servers that conform to the new WCS 1.1 spec and experiment with them on a wide range of real-world datasets. From the GALEON perspective, some of the important changes in WCS 1.1 are:

• multiple coverages in one request
• multiple fields in a coverage
• 3 spatial dimensions
• 2 time dimensions (e.g., the time a forecast was run and the forecast times within the run)
• relative time ( e.g., the latest image, the last 5 images, ...)
• non-spatial dimension (e.g., pressure or density)
• irregular grids

2. Catalogs and/or WCS getCapabilities lists? The getCapabilities request appears to be inadequate to return a list of all the coverages on a WCS server. Several people have suggested that GALEON Phase 2 include experiments that involve CS-W (Catalog Services for the Web) as well as WCS. As an illustration of the challenge, the top level THREDDS catalog represented in HTML at: http://motherlode.ucar.edu:8080/thredds/catalog.html

includes several catalogs of catalogs of different types of real time datasets. If you drill down in the "NCEP Model Data," you'll get to collections of many datasets, each of which contains hundreds of coverages. These catalogs are being updated in near real time as new data arrive. Currently these datasets are catalogued using THREDDS technology, but it would be good to have a standards-based interface as well. Without such catalogs, the WCS interface is much less effective.

I should add that those NCEP model output datasets also exhibit all the characteristics suggested for interoperability testing in item 1 above so they can be used as grist for a couple major phase 2 objectives.

3. GML dialects

There appears to be an accelerating trend to develop new XML schemas for many subdisciplines in the geosciences. Even within the world of GML, many profiles are evolving. Within the GALEON team discussions, at least 3 have come up in the context of methods for characterizing CF-netCDF characteristics in a standard form:

• ncML-GML
• CSML
• GMLJP2

Some effort toward testing the applicability and effectiveness of these approaches would be valuable.

This is a pretty full agenda, but I would not expect all the participants to work on all the items. On the other hand, it would be usefull to have at least some effort focuse in each area.

There have also been some suggestions relating to web processing and chaining services, but the general sense seems to be to leave that to the OGCnetworks -- GALEON and GSN and to collaborate with the ESIP Federation endeavors in that realm. See: http://wiki.esipfed.org/index.php/Web_Services

I am going to send a copy of this to a few colleagues who expressed an interest in the work but are not part of the GALEON team ... yet.

Please let us all know which (if any) aspects of the imposing list of objectives your group would likely participate in. Comments or corrections to any of this are welcome.

-- Ben

[edit] Sep 25

Below are a few GALEON related items.

Phase 2 Planning Documents

Among the pending documents for comment on the OGC web site is a GALEON Phase 2 Activity Plan that incorporates the elements we've discussed earlier.

http://portal.opengeospatial.org/files/?artifact_id=17088&version=1 Also, if you are planning to participate formally in the Phase 2 and did not formally participate (submit the formal documents) for Phase 1, please contact George Percivall about filling out the appropriate documents. If you already submitted those documents for Phase 1, they still apply for Phase 2.

For those of you who are not yet members of the OGC, but plan to participate in the implementation of testbed servers or experiment with clients during Phase 2, I've put together a web page that describes the practical implementation aspect of the phase 2 experiment.

http://www.unidata.ucar.edu/projects/THREDDS/GALEON/GALEON2_Phase2_Implementations.htm

Please take a look at these documents and get back to me with comments and changes.

Next Steps

Unfortunately, unavoidable scheduling conflicts make it impossible for me to attend the next two OGC technical committee meetings. But please do not interpret this as a waning of interest, enthusiasm, or energy for GALEON. My view of this is that it is imperative that we begin active implementation and experimentation as soon as the WCS 1.1 specification is adopted. There are a few "persistent demos" involving GALEON components, several new WCS 1.0 servers are already available and a couple new clients are very close, but the real testing activity will begin when we have clients and servers converted to the WCS 1.1 specification. As I understand it, that specification should be finalized in a month or so.

A Possible Online Collaboration Facility

One final note is that I'm still actively seeking an online area where all of those (current OGC members and those who have not joined yet) can interact productively on documents related to the experiments. One possibility is a new initiative called Wikiversity:

http://en.wikiversity.org/wiki/Wikiversity:Main_Page

I have attempted to start an area for GALEON-related Earth and Space Sciences informatics content:

http://en.wikiversity.org/wiki/School:Informatics

This approach may be of interest for those of you in the academic arena, but industry collaborators may also find it useful as a place for education and training materials.

Let me know what you think. Ben

[edit] Sep 28

From: Ben Domenico <bendomenico@gmail.com> Signed-By: gmail.com To: Stefano Nativi <nativi@imaa.cnr.it>, "Woolf, A (Andrew)" <A.Woolf@rl.ac.uk>, "Rudolf B. Husar" <rhusar@me.wustl.edu>, Tom Whittaker <tomw@ssec.wisc.edu>, Lorenzo Bigagli <bigagli@imaa.cnr.it> Date: Sep 28, 2006 10:19 PM

Hi,

I did get the agu abstract submitted to the session. "IN08 - Standards-Based Interoperability Among Tools and Data Services in the Earth Sciences" with the title GALEON Phase 2: Testing Gateways Between Formal Standard Interfaces and Existing Community Standard Client/server Implementations. I simply put the authors in the order you responded to my email.

Many thanks, Ben

[edit] Sep 28

A note from John Evans indicates that WCS 1.1 specification will be placed up for a vote next week. If it passes, this means we can start working on clients and servers that conform to the revised interface specification for testing in GALEON Phase 2. -- Ben