These and many other commercial free data sources use the spherical Mercator data projection (identified by European Petroleum Survey Group [EPSG] code 900913).

Lifting your astral arms free is good practise for projection. Later, you will use these astral arms to pull your astral body free of the physical.

First, grating is projected on measured free surface, and height data of each point on free surface is measured by the grating projection method.