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On 1/21/2010 12:56 PM, Kenneth Casey wrote:
Bob, Nathan, Actually, the "Conventions" attribute can handle multiple conventions in the netCDF specification. See: http://www.unidata.ucar.edu/software/netcdf/conventions.html It says: I*t is possible for a netCDF file to adhere to more than one set of conventions, even when there is no inheritance relationship among the conventions. In this case, the value of the `Conventions' attribute may be a single text string containing a list of the convention names separated by blank space (recommended) or commas (if a convention name contains blanks), for example * * :Conventions = "XXX YYY" ;*
Yes. I had seen that. But it seemed like a tiny (but significant) difference between the CF and the netCDF conventions documents.
But I hadn't noticed until now that according to this document the "Conventions" value (e.g., "CF-1.4") is no longer used as a directory name (which had led me to think that a list of conventions would cause trouble).
While the CF conventions do say to use "CF-1.4" the text of the URL you sent doesn't say you CAN'T include other conventions. I think it would not be in the spirit of CF to tell someone not to include other conventions if they are appropriate.
It had seemed to me that if the CF standard allowed a list of Conventions and since CF tries to extend the COARDS conventions, the CF standard would say the attribute should be
Conventions: COARDS, CF-1.4 not (as it does) Conventions: CF-1.4 But maybe I'm reading too much between the lines. In the end, I don't care if we (at ERD) use something like Conventions: CF-1.4 Metadata_Conventions: COARDS, CF-1.4, Unidata Dataset Discovery v1.0 or just something like Conventions: COARDS, CF-1.4, Unidata Dataset Discovery v1.0 We'll try to follow whatever the specs say.It would be great if the CF standard could be modified a little, to expressly forbid the use of a list of conventions, or expressly allow a list and specify the separator character. And if the CF standard allows a list, then it would be great if the Attribute Conventions for Dataset Discovery's "Metadata_Conventions" attribute were renamed to "Conventions".
Ken On Jan 21, 2010, at 3:14 PM, Nathan Potter wrote:Bob, Thanks for the clarification. Nathan On Jan 21, 2010, at 12:05 PM, Bob Simons wrote:On 1/21/2010 11:17 AM, Nathan Potter wrote:Bob, Roy indicated (via an offline conversation) that the "Conventions" metadata attribute is baked into the existing netCDF files at the ERD site, and that it is unlikely that a reprocessing of the data would be undertaken to correct the existing files. If that's the case then wouldn't this mean that it would be necessary to support both interpretations of the "Conventions" attribute? Or was I misunderstanding the extent of the issue w.r.t. changing the existing ERD holdings?It is true that "Conventions" (and not "Metadata_Conventions") is used in a large number of files at ERD and that it is unlikely (but possible) that those existing files will be changed. But we are working to change our program that generates new .nc files so that new files will have both Conventions: CF-1.4 Metadata_Conventions: COARDS, CF-1.4, Unidata Dataset Discovery v1.0 Since we have configured THREDDS to get metadata from the penultimate file, the new metadata will appear in almost all of our THREDDS datasets sooner (many of our datasets are near-real-time) or later. We may have to change a few datasets by hand. But the plan is to convert to using both "Conventions" and "Metadata_Conventions" for the reasons I stated earlier this morning.Nathan On Jan 21, 2010, at 10:57 AM, Bob Simons wrote:Please leave "Metadata_Conventions" as is. The problem is that the widely used CF convention specifies that the value of "Conventions" should be just "CF-1.4" and that the value is sometimes interpreted as a directory name. So it can't be a list of conventions. See http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.html#identification-of-conventions So it is useful to have a separate "Metadata_Conventions" attribute which can be a comma-separated list of convention names, e.g., "COARDS, CF-1.4, Unidata Dataset Discovery v1.0". See http://www.unidata.ucar.edu/software/netcdf-java/formats/DataDiscoveryAttConvention.html . The misuse of "Conventions" at the ERD site was my mistake. I am working to change it to (for most datasets) Conventions : CF-1.4 Metadata_Conventions: COARDS, CF-1.4, Unidata Dataset Discovery v1.0 That's my $0.02. On 1/21/2010 10:36 AM, Nathan Potter wrote:Greetings, Any idea how many people are using the UNIDATA's NetCDF Attribute Convention for Dataset Discovery?? If Roy's site is the primary (only?) example of it in actual use, and we accept Benno's point that the name attribute *Metadata_Conventions* is redundant, should we not consider amending the draft to change the attribute name from *Metadata_Conventions* to *Conventions*? (Assuming that it hasn't been push passed the draft spec: Dataset Discovery NetCDF Attribute Convention <http://www.unidata.ucar.edu/software/netcdf-java/formats/DataDiscoveryAttConvention.html>) If we don't change it might we amend the draft to explicitly make the attributes *Metadata_Conventions* and *Conventions* synonymous? Nathan On Jan 14, 2010, at 9:44 AM, Roy Mendelssohn wrote:There are metadata in our files that follows all of those conventions. In trying to relay that act, we felt this was the best way to relay that fact. So you will find the metadata required for CF, the Coastwatch conventions, and the Unidata Data Discovery Conventions. -Roy On Jan 14, 2010, at 9:40 AM, Benno Blumenthal wrote:OK, again trying desperately to understand your cryptic e-mails, http://thredds1.pfeg.noaa.gov/thredds/dodsC/satellite/SW/chla/1day.das has many of those attributes. You did, however, say String Conventions "COARDS, CF-1.0, Unidata Dataset Discovery v1.0, CWHDF"; whereas the document suggested looking for String Metadata_Conventions = "Unidata Dataset Discovery v1.0"; What you are doing, of course, makes sense. Did the original document get corrected over time? Benno On Thu, Jan 14, 2010 at 12:31 PM, Roy Mendelssohn <Roy.Mendelssohn@xxxxxxxx <mailto:Roy.Mendelssohn@xxxxxxxx> <mailto:Roy.Mendelssohn@xxxxxxxx>> wrote:No we use it extensively. Look at any of he satellite data at our TDS (http://oceanwatch.pfeg.noaa.gov/thredds/catalog.html). It is just since this is not automatically produced by the TDS that we have a program of our own that generates our catalogs. -Roy On Jan 14, 2010, at 9:18 AM, Benno Blumenthal wrote:So, to be really concrete, despite this convention of using netcdf attributes to insert metadata which you just pointed us to, you don't use it at all, you just scan your netcdf files yourself and generate the TDS XML directly. Benno On Thu, Jan 14, 2010 at 12:14 PM, Roy Mendelssohn <Roy.Mendelssohn@xxxxxxxx <mailto:Roy.Mendelssohn@xxxxxxxx> <mailto:Roy.Mendelssohn@xxxxxxxx>> wrote: We did this "by hand" (well actually we have a program that does it) in generating our catalogs not certain ow others do it. -Roy On Jan 14, 2010, at 8:56 AM, Nathan Potter wrote:Roy, Briefly scanning that page it looks like this gist of it is that one could use NcML to add/complete a "Unidata Dataset Discovery v1.0" set of metadata to a data set. THis could then be harvested by the TDS, or by other software that understood the "Unidata Dataset Discovery v1.0" convention. Is that the general idea? N On Jan 14, 2010, at 8:41 AM, Roy Mendelssohn wrote:Hi Nathan: Look at: http://www.unidata.ucar.edu/software/netcdf-java/formats/DataDiscoveryAttConvention.html -Roy On Jan 14, 2010, at 8:33 AM, Nathan Potter wrote:Greetings, I have some questions about the origin of the thredds:geospaptialCoverage element that is commonly found in THREDDS catalogs. It is my understanding that: - The TDS can generate this metadata element by interrogating certain types of source data files. - People that write their own THREDDS catalog files to be served by the TDS can add the thredds:geospaptialCoverage metadata directly to their catalogs (using whatever process they wish). Is the thredds:geospaptialCoverage also something that can be added through normal channels in NcML augmented data sets? = = = Nathan Potter ndp at opendap.org <http://opendap.org> OPeNDAP, Inc. +1.541.231.3317 _______________________________________________ thredds mailing list thredds@xxxxxxxxxxxxxxxx <mailto:thredds@xxxxxxxxxxxxxxxx> <mailto:thredds@xxxxxxxxxxxxxxxx> For list information or to unsubscribe, visit: http://www.unidata.ucar.edu/mailing_lists/********************** "The contents of this message do not reflect any position of the U.S. Government or NOAA." ********************** Roy Mendelssohn Supervisory Operations Research Analyst NOAA/NMFS Environmental Research Division Southwest Fisheries Science Center 1352 Lighthouse Avenue Pacific Grove, CA 93950-2097 e-mail: Roy.Mendelssohn@xxxxxxxx <mailto:Roy.Mendelssohn@xxxxxxxx> <mailto:Roy.Mendelssohn@xxxxxxxx> (Note new e-mail address) voice: (831)-648-9029 fax: (831)-648-8440 www: http://www.pfeg.noaa.gov/ "Old age and treachery will overcome youth and skill." "From those who have been given much, much will be expected"= = = Nathan Potter ndp at opendap.org <http://opendap.org> OPeNDAP, Inc. +1.541.231.3317********************** "The contents of this message do not reflect any position of the U.S. Government or NOAA." ********************** Roy Mendelssohn Supervisory Operations Research Analyst NOAA/NMFS Environmental Research Division Southwest Fisheries Science Center 1352 Lighthouse Avenue Pacific Grove, CA 93950-2097 e-mail: Roy.Mendelssohn@xxxxxxxx <mailto:Roy.Mendelssohn@xxxxxxxx> <mailto:Roy.Mendelssohn@xxxxxxxx> (Note new e-mail address) voice: (831)-648-9029 fax: (831)-648-8440 www: http://www.pfeg.noaa.gov/ "Old age and treachery will overcome youth and skill." "From those who have been given much, much will be expected" -- Dr. M. Benno Blumenthal benno@xxxxxxxxxxxxxxxx <mailto:benno@xxxxxxxxxxxxxxxx> <mailto:benno@xxxxxxxxxxxxxxxx> International Research Institute for climate and society The Earth Institute at Columbia University Lamont Campus, Palisades NY 10964-8000 (845) 680-4450********************** "The contents of this message do not reflect any position of the U.S. Government or NOAA." ********************** Roy Mendelssohn Supervisory Operations Research Analyst NOAA/NMFS Environmental Research Division Southwest Fisheries Science Center 1352 Lighthouse Avenue Pacific Grove, CA 93950-2097 e-mail: Roy.Mendelssohn@xxxxxxxx <mailto:Roy.Mendelssohn@xxxxxxxx> <mailto:Roy.Mendelssohn@xxxxxxxx> (Note new e-mail address) voice: (831)-648-9029 fax: (831)-648-8440 www: http://www.pfeg.noaa.gov/ "Old age and treachery will overcome youth and skill." "From those who have been given much, much will be expected"-- Dr. M. Benno Blumenthal benno@xxxxxxxxxxxxxxxx <mailto:benno@xxxxxxxxxxxxxxxx> <mailto:benno@xxxxxxxxxxxxxxxx> International Research Institute for climate and society The Earth Institute at Columbia University Lamont Campus, Palisades NY 10964-8000 (845) 680-4450********************** "The contents of this message do not reflect any position of the U.S. Government or NOAA." ********************** Roy Mendelssohn Supervisory Operations Research Analyst NOAA/NMFS Environmental Research Division Southwest Fisheries Science Center 1352 Lighthouse Avenue Pacific Grove, CA 93950-2097 e-mail: Roy.Mendelssohn@xxxxxxxx <mailto:Roy.Mendelssohn@xxxxxxxx> <mailto:Roy.Mendelssohn@xxxxxxxx> (Note new e-mail address) voice: (831)-648-9029 fax: (831)-648-8440 www: http://www.pfeg.noaa.gov/ "Old age and treachery will overcome youth and skill." "From those who have been given much, much will be expected"= = = Nathan Potter ndp at opendap.org <http://opendap.org> OPeNDAP, Inc. +1.541.231.3317 _______________________________________________ thredds mailing list thredds@xxxxxxxxxxxxxxxx <mailto:thredds@xxxxxxxxxxxxxxxx> For list information or to unsubscribe, visit: http://www.unidata.ucar.edu/mailing_lists/-- Sincerely, Bob Simons IT Specialist Environmental Research Division NOAA Southwest Fisheries Science Center 1352 Lighthouse Ave Pacific Grove, CA 93950-2079 Phone: (831)658-3205 Fax: (831)648-8440 Email: bob.simons@xxxxxxxx <mailto:bob.simons@xxxxxxxx> The contents of this message are mine personally and do not necessarily reflect any position of the Government or the National Oceanic and Atmospheric Administration. <>< <>< <>< <>< <>< <>< <>< <>< <>< _______________________________________________ thredds mailing list thredds@xxxxxxxxxxxxxxxx <mailto:thredds@xxxxxxxxxxxxxxxx> For list information or to unsubscribe, visit: http://www.unidata.ucar.edu/mailing_lists/= = = Nathan Potter ndp at opendap.org <http://opendap.org> OPeNDAP, Inc. +1.541.231.3317-- Sincerely, Bob Simons IT Specialist Environmental Research Division NOAA Southwest Fisheries Science Center 1352 Lighthouse Ave Pacific Grove, CA 93950-2079 Phone: (831)658-3205 Fax: (831)648-8440 Email: bob.simons@xxxxxxxx <mailto:bob.simons@xxxxxxxx> The contents of this message are mine personally and do not necessarily reflect any position of the Government or the National Oceanic and Atmospheric Administration. <>< <>< <>< <>< <>< <>< <>< <>< <>< _______________________________________________ thredds mailing list thredds@xxxxxxxxxxxxxxxx <mailto:thredds@xxxxxxxxxxxxxxxx> For list information or to unsubscribe, visit: http://www.unidata.ucar.edu/mailing_lists/= = = Nathan Potter ndp at opendap.org <http://opendap.org> OPeNDAP, Inc. +1.541.231.3317 _______________________________________________ thredds mailing list thredds@xxxxxxxxxxxxxxxx <mailto:thredds@xxxxxxxxxxxxxxxx> For list information or to unsubscribe, visit: http://www.unidata.ucar.edu/mailing_lists/[NOTE: The opinions expressed in this email are those of the author alone and do not necessarily reflect official NOAA, Department of Commerce, or US government policy.] Kenneth S. Casey, Ph.D. Technical Director NOAA National Oceanographic Data Center 1315 East-West Highway Silver Spring MD 20910 301-713-3272 ext 133 http://www.nodc.noaa.gov/ <http://www.nodc.noaa.gov/sog>
-- Sincerely, Bob Simons IT Specialist Environmental Research Division NOAA Southwest Fisheries Science Center 1352 Lighthouse Ave Pacific Grove, CA 93950-2079 Phone: (831)658-3205 Fax: (831)648-8440 Email: bob.simons@xxxxxxxx The contents of this message are mine personally and do not necessarily reflect any position of the Government or the National Oceanic and Atmospheric Administration. <>< <>< <>< <>< <>< <>< <>< <>< <><
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