Pitney Bowes MapInfo Vertical Mapper - Manual (Page 50)

Using the Kriging Interpolation Technique
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Vertical Mapper 3.7
If you choose all the system defaults, the kriging type will be ordinary, the experimental
semivariogram will be calculated, a model will be automatically fitted to the data, and kriging
interpolation will be performed. However, experienced users will always spend some time fitting a
model to the semivariogram. For more information about generating and interpreting a
semivariogram, see
Semivariogram Analysis on page 156 .
Exploring the Kriging: Point Aggregation Dialog Box
The Point Aggregation dialog box contains settings that will process the point file and remove any
coincident points. Coincident points must be removed in order to successfully interpolate a surface.
The Coincident Point Distance box enables you to group or aggregate data points into a single
new point with a recalculated value. As the distance setting becomes greater, the number of points
found within each circular area will correspondingly increase. This may be appropriate in dealing
with highly variable and irregularly distributed data.
The Coincident Point Aggregation section enables you to define the mathematical expression for
handling aggregated data. For example, if you choose a large coincident point distance, then
choose the Average Value option, a new set of data points for interpolation is created, spaced
approximately according to the distance setting and with recalculated values based on the average
of all points in each coincident point area. New points are placed at the geometric centre of the
original group.