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Hi Ben:I haven't had a chance to stir up a pot for awhile, so I couldn't resist on this one. Less on the abstract representation of coverages (sorry too old and too dumb, can barely understand word one of those things- I am still trying to grapple with the discussion from a couple of years ago that everything is a "feature", which implies if everything is then there is no discrimination power to the term and therefore has no functional meaning), but more on the idea that SOS, WFS, and the CDM say, for in situ data are all just different ways of representing the data. I would argue that they are not, and that there is a fundamental important difference.
First, though this is a little glib, I don't think WFS has the data model for ocean observations, and most of what I have seen just shove the data into some WFS structure because you can. So I want to focus on SOS (SWE) and CDM. To my mind, SOS is a step backwards, because it puts the focus on the sensor, rather than on the ocean. For most of the GALEON community the focus is on the ocean, and in this case the 4D (5D if we count forecast time) ocean. I am not at all convinced, given some recent emails about WMS that I had, and some recent WCS decisions, that the OGC community understands nor is ready to embrace a 4-D ocean.
Let me give an analogy. When an operation is going on in an operating room, there are all sorts of sensors connecting to the patient. yes, it is important, at times, to get the metadata for the sensor, in order to check it and calibrate and the like. But during the operation the key piece of information is the state of the patient, as can be put together from the different sensors, not the state of the sensors. SOS gives us the latter, while I would say GALEON's main concern is the state of the ocean, that is the former. The closest I have seen on the OGC world to the latter is CSML. Unfortunately, NOAA IOOS, at least as of now, did not decide to go with CSML. I would say rather than trying to harmonize apples and oranges, a failed enterprise from the start, let's work on harmonizing where the world view and data model share an underlying common viewpoint.
-Roy putting on his asbestos jacket :-) On Sep 16, 2008, at 5:41 PM, Ben Domenico wrote:
Hi,In this morning's Coverages Working Group session at the OGC Technical Committee meetings, several topics of interest to GALEON came up. Dominic Lowe was not able to attend these meetings, so I gave a presentation on his WCS client addition to the OWSLib python library and the way it's been used to give several of the GALEON WCS server sites a bit of light exercise. I put the presentation onto the GALEON wiki at:http://galeon-wcs.jot.com/WikiHome/Other%20GALEON-related%20Presentations/Exercising_WCS_with_Python_ppt___122161164045030_523301361773225?jot.downloadName=Exercising+WCS+with+Python.ppt&theme=noneSecond, Charles Roswell noted that the ISO 19123 Coverage specification (which is also an OGC spec) is up for revision if enough people and organizations think it needs revision and are willing to work on it. Note this is the ISO Coverage spec not the OGC WCS spec. 19123 is a very abstract spec that describes the general data model for coverages.Finally, there is a movement to have a joint session at the next OGC TC meeting that would focus on a discussion of a use case that involves collections of point/station data and other non-gridded datasets. The idea would be to try to figure out how WCS, WFS, and the Sensor Web Enablement Sensor Observation Service can/should be used for serving this sort of data. As I mentioned at the coverages meeting this morning, this seems particularly germane to GALEON and to some of the topics I believe the GO-ESSP group is addressing for netCDF and CF conventions this week at their meeting in Seattle.I would very much like to jump on this opportunity to have a free wheeling discussion on the topic at the next OGC TC meeting the first week in December. It's time we come up with a strategy for dealing with the many formal and community standards that touch on these non-gridded data collections that are such an important part of the GALEON community data systems. Please let me know if you are interested in pursuing this topic -- especially if you'll be attending the December OGC TC meeting and would be willing to participate in such a special session. I plan to begin setting up the logistics during the current meetings, so get back to me soon if you have suggestions for how to go about this.-- Ben
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