Hi everybody, as an active mapper focused on the topology consistence of the map, I don't think that any automatic re-import would make any good. The initial bulk imports left the map in the terrible state and I can't even imagine how badly it would be damaged if all the NHD data is re-imported.
I think it might be nice to have a simple, even text-like (Russians mappers have something similar<http://translate.google.com/translate?hl=en&sl=ru&tl=en&u=http%3A%2F%2Fvwo.osm.rambler.ru%2F>), web interface to NHD data so mappers would be able to check water objects manually and make a decision on re-importing and validating them. Best regards, Ivan. On Mon, Oct 29, 2012 at 9:04 AM, Ben Supnik <[email protected]> wrote: > Hi Y'all, > > First, I'm sorry that I didn't jump into this thread earlier. I am the > graphics lead on X-Plane, and for our latest version we switched from > TIGER+VMAP0+swbd to OSM for our vector water body and road data. In the > case of the US, this is perceived as a step backward by our users because > TIGER, while not as accurate as a lot of the OSM water data, is reasonably > complete. Now that we use OSM, we are "missing" lakes that were present in > older sim versions. > > At the time the consensus on various lists about importing was that > individual authors should import relatively small areas (e.g. single water > sheds) and check the import against existing data, rather than simply > blasting in the entire data set. So I wanted to solve two problems to make > things easier for users who had time and motivation but not data processing > skills: > > 1. Getting NHD data. At the time the NHD data was not available in > shape-file format; some very nice person at the USGS basically burned me > DVDs of the whole data set and mailed them to me, because the data was not > online. > > 2. The conversion required running a non-GUI tool, which meant having > command line skills, etc. > > So I ran the import script over the entire data set and uploaded the > resulting .osm files so individuals could use them. There was a third step > I was hoping could be solved: if you new to OSM, importing data isn't > trivial. Richard Fairhurst had a cool feature in Potlatch 2 where PL2 > could be told of the presence of a vector layer and import it visually. > But I was never able to get the data to work with PL2. > > I had to put the whole project on hold as X-Plane's ship date loomed > closer and things went from crazy to really-freaking-crazy at work. > > So to answer a few of Paul's questions: > > > - They're of 2011 data, not the latest NHD data >> > > Yep -- at the time I started the project it was a rip of 'latest', but > that was a while ago. :-) > > > - I wasn't able to find a rules file from bsupnik for the conversion, so >> they can't be rerun with latest data. He hasn't been active on the lists >> since 2011 and hasn't replied >> > > I used shp-to-osm-0.8.2, jar'd by someone else (I am not a big java nerd, > sorry) and the latest rules at the time from the Wiki. If it is useful, I > can send anyone who wants them a rip of the rules file I was using at the > time and/or the JAR, buuuut... > > > - The NHD data model changed since 2011 >> > > Yeah, I was something like that a few months after I put this down and > went "oh hell...". I haven't had time to look at what happened; is the > data model a major revision to the point where everything I did makes no > sense, or is it just renaming of fields? > > Other issues about the import: > - I wouldn't say it is "split" from multiple files - rather I would say it > is not joined - that is, the splits are the sub-basin splits that I think > persist in the NHD. Actually, I take that back - I think the tool chain > intentionally avoids really huge OSM entities to avoid imports that can > fail. > > - There should be OSM codes like waterway=bla on at least -some- of the > data. The import program rules from the time did include FCODE and FTYPE > and had no facility to drop entities that had only NHD but no OSM tags. At > the time this was also considered not-so-good, but I wasn't in a position > to rebuild the tool. > > Finally, just my 0.02: I am not an OSM expert and not an import expert > buuut in my uninformed opinion, having original 'foreign' keys on an > imported database isn't very useful. The import guideline is to sanely > merge the import with existing data, and the goal is to create something > 'osm native' when done, hence the importance of OSM tags and the notion of > not importing data with no OSM meaning. > > I think OSM really needs to be treated as one giant layer with > heterogenious tags. Imagine that a lake is missing from NHD. A user opens > potlatch and draws it, puts water=lake, and walks away, no FCODE or GNIS_ID > or anything like that. How can a consumer of OSM data handle this case? > Only by looking at semantic data like water=lake, and by analyzing the > union of all OSM data that has 'interesting' tags. > > Now we go to re-import NHD - is this ever going to happen? (First: given > how hard it's been to get NHD in even once, I am skeptical. :-) Every > watershed has to be hand re-merged again. > > Where I'm going with this is: I think imports should not be viewed as > 'layers' into OSM; if you ever want to look at NHD with a layer, export OSM > into your favorite GIS, import NHD into your GIS too and now you have > layers. OSM imports are destructive merges and need to be carefully > managed as such, with the target data format being OSM-centric. > > So at the time I was annoyed that we couldn't just import all of NHD at > once and 'get lakes everywhere' but while that would get a lot of > waterbodies into empty places, it's probably not good for OSM or the US > mapping community. > > Okay, that's the end of my rant, which is probably either something > everyone else already knows or completely wrong or both. :-) Poke me if > you have more q's or need materials....I think I still have the original > raw 2011 NHD on DVD if anyone wants it, although it is now stale. > > cheers > Ben > > > -- > Scenery Home Page: http://scenery.x-plane.com/ > Scenery blog: http://www.x-plane.com/blog/ > Plugin SDK: > http://www.xsquawkbox.net/**xpsdk/<http://www.xsquawkbox.net/xpsdk/> > X-Plane Wiki: http://wiki.x-plane.com/ > Scenery mailing list: > x-plane-scenery@yahoogroups.**com<[email protected]> > Developer mailing list: [email protected] > > > ______________________________**_________________ > Talk-us mailing list > [email protected] > http://lists.openstreetmap.**org/listinfo/talk-us<http://lists.openstreetmap.org/listinfo/talk-us> >
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