Hi, On Fri, 22 Oct 2010, Lowry, Roy K wrote:
I wonder how many existing CF data files would have the meaning of their time channel changed were this suggestion to be adopted.
I am sure many. In some cases it might even make them accurate. :-) At some level, it's a tradeoff between "breaking" existing data descriptions and creating a more robust standard. Whether my suggestion creates a more robust standard or not is up for debate. It does align it more closely with the ISO standard, and I think there's something to be said for that.
If I were Julia I would be reworking my data so that the time channel was true UT. I've had so many problems in the past with local time co-ordinates........
It's not data I'm generating, but rather data provided by a PI who has determined that this is how he wants to present his data. I believe the idea is to be able to view a wide geographic area over the same effective local time. It's a composite image. If you can tell me how to represent these multiple UTC times for one variable using the existing CF conventions, then I'll try to do so. I believe CF limits me to specifying one time zone for a particular time dimension. Re-working the data so that it's broken up into separate time zones would, as I understand it, mean splitting up the data variable into multiple variables, each with their own time dimension, which is not what the data provider wants to do. Splitting the variable would require the user to put the pieces back together in order to see the image as the data provider intended. As far as I can tell, following the ISO interpretation of the time zone indicator does exactly what I need without ambiguity. I'd like to describe the data in a way that's perfectly compliant with the CF convention, but in this case I don't see a way to do so. Thanks, Julia -- Julia Collins National Snow and Ice Data Center http://nsidc.org/ [email protected] +1 303.492.6405 _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
