| Term: | BoundaryNormalSystem |
| Definition: |
Boundary normal coordinates, as their name implies, are defined relative to some boundary such as the magnetopause or the bow shock. They allow the data to be ordered in a way which is related to that boundary. The L and M axes, equivalent to x and y, lie in a plane tangential to the boundary - and the N axis, equivalent to z, is normal to the boundary. |