On Tue, Jun 14, 2016 at 8:24 PM, Kevin Kenny <kevin.b.kenny+...@gmail.com> wrote: > Now that I'm done with the NYC DEP Watershed Recreation Areas import, > I've got some bandwidth to spend on this cleanup again.
I've added a sketch of the plan on the existing import page, http://wiki.openstreetmap.org/wiki/NYS_DEC_Lands Once again, the reimport will be only semi-automated, with new multipolygons and tags being proposed over narrow geographic areas but then stitched into the map manually. In no case do I wish to overwrite any work that a mapper has done that still appears valid. I will be discarding a fair number of armchair edits apparently conducted in response to automated warnings about data quality, which really did little to improve the situation. The reimport, in addition to sorting out the tagging, will clear up a great many awkward misalignments in places like http://www.openstreetmap.org/relation/6304830#map=13/42.2111/-74.3611 - where the Balsam Mountain and Pine Island Mountain units are correctly aligned, while the Hunter-West Kill Mountain Wilderness and Rusk Mountain Wild Forest are not. There are currently gaffes like that all over the Catskills. The root cause appears to be that some program in the pipeline - perhaps in the import, perhaps at the DEC - got the wrong conversions among the New York East state coordinate plane (NAD27) on which the state Department of Transportation projected its quadrangle maps, the Zone 18N UTM (NAD83) coordinates that NYSGIS now prefers, and the WGS84 coordinates (either plate carrée or spherical Mercator) that are used in OSM. Since the projection errors are not consistent from parcel to parcel, I suspect that the error was at the state's end. It appears to be corrected in recent versions of the data set. (It also makes most of the property lines contiguous with lines on the Greene County tax rolls, which are also available on line, giving the possibility of an independent cross-check of the data.) _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
