Companion

Object that defines coordinate reference systems for projecting geographical points into pixel (screen) coordinates and back (and to coordinates in other units for WMS services).

Serves as the base for CRS that are global such that they cover the earth. Can only be used as the base for other CRS and cannot be used directly, since it does not have a code, projection or transformation.

Rarely used by some commercial tile providers. Uses Elliptical Mercator projection.

The most common CRS for online maps, used by almost all free and commercial tile providers. Uses Spherical Mercator projection. Set in by default in Map's crs option.

A common CRS among GIS enthusiasts. Uses simple equirectangular projection.

A simple CRS that maps longitude and latitude into x and y directly. May be used for maps of flat surfaces (e.g. game maps). Note that the y-axis should still be inverted (going from bottom to top). distance() returns simple euclidean distance.