On Wed, Jan 14, 2015 at 12:37 PM, Nikos Alexandris <[email protected]> wrote: > Nikos Alexandris: > >>>> I can't get wrs2_descending.shp file (from >>>> <http://landsat.usgs.gov/documents/wrs2_descending.zip>) to import >>>> sans errors (grass7). No matter the snap threshold. Anyone recently >>>> imported it? > > > Markus Neteler wrote: > >> I think that their overlapping areas cannot be represented as pure >> topological model. > > > Right.
Yes, overlapping areas can be represented as a topological model through M:N mapping: each area can belong to several categories, several areas can have the same category. If you want to get the coverage for a particular Landsat scene, just select the path and row with where="PATH = x and row = y". See also the manual of v.buffer for a similar example. > >> Hence, you need to maintain them (AFAIK it is the -c option in v.in.ogr). >> Please correct me if I am wrong. > For this shapefile, original polygons can not be maintained (incorrect boundaries, centroids exceeding number of areas). Markus M > > I'll do so. > >> The question is: what's you scope? Visualization? > > > A complete set of tools for Landsat data, inside GRASS, requires a proper > trimming utility. The existing add-on i.landsat.trim does not satisfy my > needs. > > Using a slightly modified version of > <ttps://github.com/robintw/LatLongToWRS>, which I'll integrate into (my > yet-unifinished personal mini-project) <i.landsat.wrs2trim>, one will simply > need to tell which landsat scene(s) (or, optionally, the desired path & row > combination(s)) should be border-pixel-trimmed. > > I've decided to go the hardway, meaning, let the user or the script, get the > "wrs2_descending.shp" file, import it in GRASS and let the module do its > work. Or, perhaps, share along with the module a clean vector data set (in > GRASS' native format? compressed?). > > Nikos > > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
