[R-sig-Geo] Simple external drift kriging question

[Tom Gottfried]

Hi Chris,

Am 07.03.2011 17:44, schrieb CC Greene:
> Hello,
> 
> I am new to geostatistics. I was hoping someone could answer the following
> question:
> 
> When trying to do external drift kriging, I understand that you create the
> variogram from the residuals. Then, my question is when you actually do the
> kriging, do you interpolate the residuals and add them to an ordinary kriged
> field?

The residuals, that are interpolated by kriging, are added to the values obtained from interpolation
via regression. The gstat package does this for you if you specify an independent variable e.g. in
gstat() or krige().

> Or, can one just take the variogram derived from the residuals and apply it
> to the raw data when kriging.

No, as the variogram derived from the residuals does only represent the spatial dependence in the
residuals, not the raw data.

regards,
Tom

> Thank you for your time and a simple response.
> 
> Chris
> 
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> 
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