Coordinate units

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Two kind of coordinate units are supported:

 

Spheric / Latitude-longitude (global / local)
Cartesian / Projected (local)

 

When working with spheric coordinates, all distance calculations are performed using great circle distances and the Earth is considered a perfect sphere with radius 6378.13 km.

 

When working with Cartesian coordinates, all distance calculations are performed using straight Pythagoras formula. Several different Cartesian units are supported.

 

Global projections such as Web Mercator and more are not supported. They use meters as coordinate unit, but the scale factor depends upon the latitude.

If you use it, you will not get any error messages, but the lengths will come out wrong, when you are not on Equator.

 

It is worth noting, that RW Net never performs any transformation between coordinate systems. It always works with the native coordinates of the base dataset used when creating the network. It will return strange results, if you set the coordinates as spheric, while they are really meters or vice-versa. It is YOUR responsibility to make sure this is correct.

 

See also TCoordinateUnit