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Pitney Bowes MapInfo Vertical Mapper User Manual

Page 28

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Choosing an Interpolation Technique

26

Vertical Mapper 3.7

2. How accurate is the data?

Some techniques assume that the value at every data point is an exact value and will honour it
when interpolating. Other techniques assume that the value is more representative of an area.

3. What does the distribution of the points look like?

Some interpolation techniques produce more reasonable surfaces when the distribution of points
is truly random. Other techniques work better with point data that is regularly distributed.

Data Type

Possible Interpolation

Elevation

Triangular Irregular Network (TIN), Natural Neighbour (NN)

Soil Chemistry

Inverse Distance Weighting (IDW), Kriging

Demographic

NN, IDW, Kriging

Drive Test

NN

Point Value Accuracy

Possible Interpolation Technique

Very Accurate

NN, TIN, Rectangular

Not Very Accurate

IDW, Kriging

Point Distribution

Possible Interpolation Technique

Most interpolation techniques work well with randomly scattered
data points.

NN, TIN, IDW, Kriging

Highly clustered data presents problems for many interpolation
techniques.

NN, IDW, Kriging

TIN – for slightly clustered data points