Hi Wenli,
Thanks for scrutinizing the NetCDF / WCS guide so thoroughly. I've attached my comments
& suggested edits to what you wrote. I see that Ben has already incorporated your
notes into the GALEON Webpage
<http://www.unidata.ucar.edu/projects/THREDDS/GALEON/WCSnetCDFencoding.htm>;
fortunately my edits are minor. They are in a nutshell:
1 - I usually distinguish "scalar" vs. "compound" (rather than "parametric")
2 - In the opening paragraph, it would be good to stay closer to the ISO 19123 model, where a coverage has only one
range, which contains "records." The "19123 coverage" associates to each location in the domain a
single "record," which may have one or more "values" in it (and each of these values may be scalar
or compound -- though 19123 doesn't say much about that other than to say the values may have arbitrarily complex
structure).
3 - I wonder about the typing / dimensions issue when we equate (e.g.,) an infinitely
thin rectangle (2D) with a line segment (1D) as you do under "2) Number of axes
(dimensions)." Can this be handled easily in NetCDF?
- John E.
Wenli Yang wrote:
Hello,
Attached please find my comments on the "Binary Encoding of WCS
Coverages in NetCDF" prepared by Ben etc. I hope that the comments
can serve to clarify some WCS data model concepts and the relationship
between WCS and netCDF data models. I am CCing this to the WCS RWG so
that WCS expert may review, if they have time, to see if my
interpretation of the WCS grid data model is correct. I feel that it
will be helpful to have both GALEON and WCS groups work together on
this due to conceptual difference on the data models. As I mentioned
in the comments, I think that one of the most important aspects is
probably to have a common understanding on the
expression/use/referencing of coordinate reference system (CRS),
including both geo-coordinate and array/grid coordinate.
Wenli
PS: I posted this yesterday from my GMU email but didn't get through
probably because that email address was not in the GALEON list (I
didn't cc to WCS WRG yesterday). I apologize if you get duplicated mail.
--
John D. Evans, Ph.D. <john.evans@xxxxxxxxxxxxx>
NASA Geoscience Interoperability Office / GST, Inc.
1-301-286-0803 / 1-240-542-1133
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