I indeed need to express distances in meters. This is a sinusoidal grid with Varying cell resolutions, matching the length of web mercator tiles at the equator. I could use any value greater or equal to the defined sphere radius, but not smaller. To be consistent, it should be equal.
Ben Am 18.06.16, 02:50 schrieb "Dirk-Lüder Kreie" unter <[email protected]>: >Am 17.06.2016 um 21:39 schrieb Stadin, Benjamin: >> Hi, >> >> I want to double check the earth radius used by OSM and zoom levels is >> exactly 6372.7982 as said here: >> http://wiki.openstreetmap.org/wiki/Zoom_levels. >> >> I couldn¹t find this as constant in the sources yet. I¹m creating a new >> storage system for vector tiles, independent of a projection. > >This constand is completely unnecessary for the projection itself unless >you want to express distances in meters (or any other unit of length), >since lat and lon are angles from the equator and meridian respectively. >As long as you don't need a scale you can ignore the radius or set it to >any arbitrary number (although 6372.7982 km is not a bad choice) > >-- > >Dirk-Lüder "Deelkar" Kreie >Bremen - 53.0901°N 8.7868°E _______________________________________________ dev mailing list [email protected] https://lists.openstreetmap.org/listinfo/dev
