Contents
Is Web Mercator in meters?
The Web Mercator coordinate system used by Google/Bing/ArcGIS Online uses meters.
Does Mercator projection preserve distance?
The Mercator projection doesn’t preserve area correctly, especially as you get closer to the poles. On the other hand, one kind of projection that doesn’t distort area is the Cylindrical Equal Area. Notice here how Greenland looks the right size as compared to South America.
What are the map units for the Mercator projection?
Mercator is a conformal map projection. Directions, angles, and shapes are maintained at infinitesimal scale. Any straight line drawn on this projection represents an actual compass bearing. These true direction lines are rhumb lines and generally do not describe the shortest distance between points.
Does WGS 84 Preserve distance?
WGS 1984 Web Mercator and WGS 1984 Web Mercator (Auxiliary Sphere) use a conformal projection that preserves direction and the shape of data but distorts distance and area. Note that distances are very distorted in the east-west direction, north or south of the Equator.
Is UTM equal area?
Furthermore, since TM and UTM are used as map sheets in many countries, the conformal projections (TM, UTM) are compared with the equal-area projections.
Why is Web Mercator used?
Web Mercator Coordinate System It is the de facto standard for web maps and online services. With this coordinate system, the geodetic coordinates defined on the WGS 84 datum are projected as if they were defined on a sphere, using a sphere-based version of the Mercator projection.
Is WGS84 a projection?
Wikipedia’s page on map projections also does a very good job of explaining the different types of PCSs, what distortions are caused, etc. Many projections also have their own pages explaining their history, math, etc. Nevertheless, WGS84 is not a projection.
Why is WGS84?
It is a global datum, which means that coordinates change over time for objects which are fixed in the ground. Therefore it is important that coordinates in terms of WGS84 have a time associated with them, especially where the best levels of accuracy are required. Note: There are multiple realisations of WGS84.
Is there a way to emulate the Mercator projection?
Two methods exist for emulating the Mercator projection used by the web services. If the Mercator implementation supports spheroids (ellipsoids), the projected coordinate system must be based on a sphere-based geographic coordinate system. This will force the use of sphere equations.
How to calculate distance from Web Mercator coordinates?
According to the above-mentioned presentation, the following method could be used to calculate more accurate distances from web mercator coordinates. Given dx — horizontal coordinate difference (W-E direction), and dy — vertical coordinate difference (S-N direction):
Which is the best version of Mercator for ArcGIS?
Its variant, the Web Mercator projection, is standard for web maps and online services. The projection is often misused for world maps, wall charts, and thematic mapping on web maps. There are four variants available in ArcGIS: Mercator is also known as Mercator variant B.
What kind of projection does Google Maps use?
Recently, ArcGIS Online services became available in the same “Web Mercator” projection used by Google Maps and Bing Maps. If you use the new ArcGIS Online services, avoid the temptation to perform measurements of polylines and polygons in Web Mercator.