Differences

This shows you the differences between two versions of the page.

--- braindump [2018/10/08 23:23] – [Web Mercator (EPSG:3857/EPSG:900913)] allchin09
+++ braindump [2018/10/08 23:26] – [Web Mercator (EPSG:3857/EPSG:900913)] allchin09
@@ Line 166: / Line 166: @@
 ===== Web Mercator (EPSG:3857/EPSG:900913) =====
-Used in many popular web mapping applications (Google/Bing/OpenStreetMap). Uses spherical development of ellipsoidal coordinates. Relative to an ellipsoidal development errors of up to 800 meters in position and 0.7 percent in scale may arise. It is not a recognized geodetic system: see WGS 84 / World Mercator (CRS code 3395).
+Used in many popular web mapping applications (Google/Bing/OpenStreetMap). Uses spherical development of ellipsoidal coordinates. Relative to an ellipsoidal development errors of up to 40 km may arise. It is not a recognized geodetic system: see WGS 84 / World Mercator (CRS code 3395).
 For details on the issues using Web Mercator for geospatial applications, see the report from the US NGA (National Geospatial-Intelligence Agency) on [[http://earth-info.nga.mil/GandG/wgs84/web_mercator/(U)%20NGA_SIG_0011_1.0.0_WEBMERC.pdf|Implementation Practice