Wow, for once Frederik and I agree on something having to do with an import!
(I'm teasing, of course.) Even better than "remove the object from the import list so you don't create a duplicate" is "conflate the objects so that you get the best information from both sources." But we all knew that: conflation > avoidance > duplication. Conflation is more work, though, and usually needs at least consultation with the local mapper. That's what I did on a recent project to make sure that the State Parks in New York were all there - using the laborious process of reconstructing their boundaries from the tax rolls. If I saw a substantial difference in the park boundary between what the tax rolls showed and what was in OSM, I got in touch with the mapper who put the park boundary there in the first place. In every single case, the response from the local mapper was that they were tracing differences in landcover from orthophotos, and they welcomed boundaries from a more authoritative source. All the rest of the data (that is to say, the tagging) - the local mapper's information would win out over the "official" information unless I could verify personally that the "official" version was correct. (For well over half the state parks, nobody had mapped them yet..) I didn't call this one an 'import' because all edits were applied manually, using carefully selected data from the tax parcels and a lot of manual patchwork to make the boundaries coherent. It's fairly safe to automate conflation only if you can prove (generally through an object's version history) that the object you're destroying was the result of an earlier import, and you have a reasonably comprehensive understanding of how the earlier import was done. I did a lot of that with the reimport of the "New York DEC Lands" file - replacing old information with new, and in some cases then reapplying changes that the locals had made. Now, having done a couple, I'll concur with Frederik that imports are insanely difficult to get right, generally an order of magnitude more work than the proponent expects. On Mon, Sep 26, 2016 at 12:18 PM, Frederik Ramm <[email protected]> wrote: > Dewi, > > On 09/26/2016 07:26 AM, Dewi Sulistioningrum wrote: > > The source data and permission letter for data license from government > > disaster in East Java. > > I can't see the permission letter? > > I have looked at the infrastructure import web page and I think you > should perhaps add a sentence like "if you find that there is already a > node or building mapped in OSM, remove that object from the import list > so you don't create a duplicate" or so. > > Best > Frederik > > -- > Frederik Ramm ## eMail [email protected] ## N49°00'09" E008°23'33" > > _______________________________________________ > Imports mailing list > [email protected] > https://lists.openstreetmap.org/listinfo/imports >
_______________________________________________ Imports mailing list [email protected] https://lists.openstreetmap.org/listinfo/imports
