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Due to the current gap in continued funding from the U.S. National Science Foundation (NSF), the NSF Unidata Program Center has temporarily paused most operations. See NSF Unidata Pause in Most Operations for details.
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See comments inline. Ron
Just one note, quickly added: Wright, Bruce wrote:1. Coverages and features are different...WFS and WCS evolved as two distinct services to meet different requirements for accessing data and metadata.this is past and presence, IMHO.2. A coverage is a feature...features and coverages are different 'cross-sections' through the information - Simon Cox presents this nicely by considering the information as tabular, with a row represents a feature (a series of individual property values) and a column representing a coverage (different values of the same property) - and the WFS and WCS should be harmonised.hm, that seems like adding a third, radically new concept to unify the two others. Why not simply say "a coverage is a feature which enjoys special treatment, as laid down in the WCS".3. A feature is a coverage...coverages are already effectively being encoded in GML for some WFS requests that need to return the variation of a set of parameters over space/time (normally small data volumes); again, this suggests that the WFS and WCS should be harmonised.
[RTL] In the ISO model, Coverages are Features and this approach was followed in GML since Version 3.0. A number of early WFS implementations provided raster coverages - usually as results of Observations - this discussion seems to have been going on for quite a number of years (~ 10).
well, I have nothing against GML as one _additional_ data format (and a proof that something is possible). All the mapping people I have talked to, however, want to first webify their vector material and then their rasters - current practice, alas, has made WFS the first-born son ;-)4. Coverage is a property of a feature... WCS is a convenience interface, which should eventually replaced by an enhanced WFS, which adds a GetCoverage request (or an OPeNDAP request!)
[RTL] It makes perfect sense to have coverage valued properties of a feature. For example, a photo-log of a road or simply the surface texture of the road could be represented as a coverage.
oops, that sounds complex - just a property (aka attribute) of a feature? We might adopt #2 and come to the same conclusion.Personally, I think these are all true to some extent (not sure 3. above is a good thing though!). However, which viewpoint you take determines how you develop and implement these web services going forward (e.g. my explicit 'conclusion' on 4. above!).
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