OpenStreetMap
Weird Parallel E/W Lines
Publicado por bhietsch o 27 de Agosto de 2020 en English. Última actualización no 29 de Agosto de 2020.Anyone know what the deal with these lines is? They seem to run between the prime meridian and the anti-meridian, but only render at zoom level of 4. My first thought was that they may have something to do with the arctic circle, but they look to be a degree or two south of it.
Parola
Comentario de highflyer74 no 27 de Agosto de 2020 ás 20:38
Not visible here though… I will check on a different computer tomorrow.
Comentario de highflyer74 no 28 de Agosto de 2020 ás 05:30
Check done, no signs of lines.
Comentario de imagico no 28 de Agosto de 2020 ás 09:38
These lines - as can be derived from where they are located - result from boundary line segments (here from admin_level 2 boundary relations) crossing the 180 degree meridian. Since practically almost all geodata processing software by default interprets line segments as if geographic coordinates were cartesian coordinates and therefore assumes any such segment no matter how short it actually is to wrap around the whole earth along the parallel you need to avoid such segments by splitting any geometry crossing the 180 degree meridian along the meridian. If a mapper not aware of this carelessly moves a node across the 180 degree meridian the result is like what you point out (in this case probably fixed in osm.org/changeset/88746336)