Natural Neighbor

The Natural Neighbor gridding method is quite popular in some fields. What is Natural Neighbor interpolation? Consider a set of Thiessen polygons (the dual of a Delaunay triangulation). If a new point (target) were added to the data set, these Thiessen polygons would be modified. In fact, some of the polygons would shrink in size, while none would increase in size. The area associated with the target's Thiessen polygon that was taken from an existing polygon is called the "borrowed area." The Natural Neighbor interpolation algorithm uses a weighted average of the neighboring observations, where the weights are proportional to the "borrowed area."

The Natural Neighbor method does not extrapolate data beyond the convex hull of the data locations (i.e. the outline of the Thiessen polygons).

Specifying Natural Neighbor Options

In the Property Manager Gridding page, select Natural Neighbor as the Gridding method and then click the Advanced Options

button to display the Natural Neighbor Options dialog. For more information about anisotropy options see Anisotropy.

The main reference for this method is Sibson (1981), however, also refer to Sibson (1980) and Watson (1994). Watson (1994) discusses the Natural Neighbor gridding technique in some detail, though MapViewer does not use any of Watson's source code.

Sibson, R. (1980), A Vector Identity for the Dirichlet Tesselation, Math. Proc. Cambridge Phil. Soc., v. 87, p. 151-155.

Sibson, R. (1981), A Brief Description of Natural Neighbor Interpolation, Interpreting Multivariate Data, V. Barnett editor, John Wiley and Sons, New York, p. 21-36.

Watson, Dave (1994), Nngridr - An Implementation of Natural Neighbor Interpolation, David Watson, P.O. Box 734, Clarement, WA 6010, Australia.