Pitney Bowes MapInfo Vertical Mapper - Manual (Page 39)

Chapter 3: Creating Grids Using Interpolation
User Guide
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With the search radius defined by the Search Radius setting, the Weight to Furthest
Point Only check box enabled, and the maximum number of points set to 20, the
decay curve will be based on the search radius indicated by the dotted line.
Note .The default values for the search criteria and Number of zones, Zone orientation, and
Radius Multiplier options are appropriate for most data.
The File name box enables you to enter a new file name.
The Extents button displays a summary of the geographic size and the z-value range of the original
point database, the density of the points, and the data value units.
Natural Neighbour Interpolation
Natural neighbour interpolation is a geometric estimation technique that uses natural neighbour
regions generated around each point in the data. This technique is particularly effective for dealing
with a variety of spatial data themes exhibiting clustered or highly linear distributions.
The natural neighbour technique is designed to honour local minimum and maximum values in the
point file and can be set to limit overshoots of local high values and undershoots of local low values.
This technique thereby enables the creation of accurate surface models from data that is very
sparsely distributed or very linear in spatial distribution.
The interpolated surface is tightly controlled by the original data points by honouring
the value at each point. It also provides the option to over- or under- shoot point
values.