Mapping with nvdb is mostly the best armchair mapping, but I agree with Zvenzzon. Would go so far as to say if you replace geometry with nvdb it is hard to be responsible.
I use it for correcting ortoerrors. Troger is the DEM available as a tile source now? /emj Den tors 20 mars 2025 22:01Anders Torger via Talk-se < [email protected]> skrev: > While there quality in NVDB does vary (it's a collection of multiple > sources) and geometry simplifications does occur, it's on average very > good. You cannot get the same accuracy from Bing or ESRI imagery, if you > want to get similar precision from ortophoto you would need lantmäteriet's > own. Sure if you have your own diff-GPS system you can get more precise, > but most maps from some sort of orthophoto, usually with limited elevation > correction leading to fairly large positional errors. > > Ideally you should use NVDB + Orthophoto + strava heatmap for sanity > checking + local knowledge where available. I've mapped tens of thousands > of roads in this manner in northern Sweden and quality of NVDB is very > good, while roads mapped on (especially older) ortophoto in hilly regions > can be very far off the mark. In city geometry stuff get a bit more > complicated, because there may be simplifications made for navigation which > may not match with OSM tradition, and there you need to deviate at times. > We have an ongoing manual import project with documentation of limitations > and caveats. You should never import blindly, that's why the NVDB import > project (or rather manual merging) takes such long time. If you see errors > like duplicated geometries, clearly the mapper hasn't paid much attention > to his or her merging effort. Any source if misused leads to poor results. > > It's best to use multiple sources and if working in Sweden NVDB should for > sure be one of them, and if the only positional data you have is NVDB and > an ortophoto from Bing or Esri, NVDB is nearly always better positioned, > with the exception of geometry simplification possibly occurring on > multi-lane roads, or sometimes very new forestry roads with preliminary > geometry and other rare exceptions. Naming of forestry roads can be wonky > in places, as the reporting can be patchy and approximate depending on > forestry company responsible for the reporting. Naming of roads in cities > are usually of very high quality. > > The problem with OSM in Sweden is that the coverage can be patchy in > places where there are few active mappers, and some mapping can be rather > outdated. The big cities are usually well covered, or home cities of super > mappers. There are large areas in Sweden which is only occasionally paid > attention to, and there mapping work from people without access to the > ground is needed, and in such a situation using NVDB in a responsible way > as one of the key sources is the best way to go. > > However, if the mapper doesn't really want to make the effort to use NVDB > responsibly and not knowing about its limitations or how you relate to > existing mapping, it's best to not use it of course. > > /Anders > > On 2025-03-20 13:07, Peter Svensson wrote: > > I disagree. The only things that shows exact locations of Swedish roads > are the ground itself. Everything else is approximations and > simplifications which are by definition "not exact". I've lost count of how > many things I've cleaned up after various NVDB import efforts, such as > incorrect names and duplicated/questionable geometries. > > I encourage use of other sources than NVDB for mapping missing roads. > > With regards, > > zvenzzon > > > > Den tors 20 mars 2025 12:31Markku Siipola via Talk-se < > [email protected]> skrev: > > Your answers shows you are not aware of NDBD, the National road database. > This source should always be used, and not any source. The NVDB shows the > exact locations of Swedish roads. It's waste of time of not using this db. > > > > > > Den 2025-03-20 kl. 08:38, skrev Valeria Yukovich via Talk-se: > > Hello, Snusmumriken! Thank you for the questions. > We will be using available sources which are appropriate for mapping on > OSM (satellite and street-level imagery, for example). Besides that, we > will be also using Mapbox telemetry data and GPS traces in cases when > there is limited evidence. More information about Mapbox telemetry data can > be found here: https://www.mapbox.com/telemetry. > Speaking about our experience with other countries, we mostly encountered > missing roads in newly built residential areas and around commercial > objects, which we did not map in cases if the evidence (street-level > imagery or up-to-date satellites, information from the telemetry) was not > enough for mapping. > > On Wed, Mar 19, 2025 at 12:18 PM Snusmumriken < > [email protected]> wrote: > > On Tue, 2025-03-18 at 16:46 +0300, Valeria Yukovich via Talk-se wrote: > > Hello from the Mapbox team! > > > > Our team has been mapping missing roads since May (as described > > here: https://community.openstreetmap.org/t/mapbox-organized-editing- > > missing-roads/113678) and currently we are preparing to expand the > > effort to Sweden. > > Hi > > I have basically two questions: > - What sources will you be using in Sweden? > - What are the most common problems you've encountered in other > countries? > > > _______________________________________________ > Talk-se mailing > [email protected]https://lists.openstreetmap.org/listinfo/talk-se > > _______________________________________________ > Talk-se mailing list > [email protected] > https://lists.openstreetmap.org/listinfo/talk-se > > > _______________________________________________ > Talk-se mailing list > [email protected] > https://lists.openstreetmap.org/listinfo/talk-se > > > _______________________________________________ > Talk-se mailing list > [email protected] > https://lists.openstreetmap.org/listinfo/talk-se >
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