Source: http://docs.codehaus.org/pages/viewpage.action?pageId=62876
I don't know anything about goals 1 & 2. Goal 3 seems appropriately positioned. Prologue to the rest: "Features" and "Coverages" ala ISO do not seem to correspond to that which is served by a Web Feature Service / Web Coverage Service. In particular, WCS/WFS divide the problem into the Raster/Vector problem spaces, and ISO divides the problem into single-valued/multi-valued problem spaces. A WFS, serving a particular feature, performs many of the functions which belong to a DiscreteCoverage in the ISO world. (e.g., spatially indexed lookup of values from a collection of range/value pairs, where the values are homogeneous within the collection; range=defaultGeometry; value=everything else). I remain blissfully ignorant of ISO's efforts to adopt WFS into their framework (19141, I think). Short version: if I was pressed to describe what an WFS is, I'd have to say it is a discrete coverage implementation using Web Services technology. A WCS would then be an implementation of DiscreteGridPointCoverage implementation. Messy, because this implies a parent-child relationship between WFS & WCS. Goal 4: Not sure I understand what is the main point. Why limit ourselves to POJO databases? Conversely, if we can create featuretypes from inspection of an arbitrary JDBC data source now, why does this not carry over to POJO databases? Why do POJO databases require an extra abstraction layer instead of just a driver? I'm not sure I "get it" enough to ask anything intelligent. Goal 5: Unsure as to the proposal. Is this an addition to a WFS which basically allows the server to "cascade" to a WCS? Are we trying to wrap the bare bones raster data with GML representative of a Feature possessing the characteristics of a 19123 Coverage? Should we also consider repackaging the whole shootin' match into GML: each returned pixel/grid cell gets its own record in the returned GML (or shapefile)? In ISO speak, someone might want to treat DiscreteGridPointCoverage data as if it were a plain DiscreteCoverage. Goal 6: This is the Holy Grail! I know exactly whazzup with this one! For some thoughts on how vertical/temporal subsetting may be handled, see the analysis of WMS 1.3.0 on the Multidimensional WCS page. They've provided for this functionality. ( http://docs.codehaus.org/display/GEOS/Multidimensional+WCS) Perhaps future versions of WMS/WFS will adopt the same strategy? I'm not sure you're going to be able to use a WFS to query a WCS based on the grid cell values unless you adopt a cascading mentality. The WFS is going to have to hide the WCS entirely, and can't just include a link so the user can get the data directly. One minor point: if it's served by a WCS, it's a discrete grid point coverage. No continuous coverages are served over the net. Bryce ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Geotools-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-devel
