RE: AI-GEOSTATS: Dealing with Universal Kriging

2002-04-10 Thread Isobel Clark

Alessandro

Thanks for the contribution. 

If Universal Kriging is applied, there is no need for
simulation or multi-indicator approaches to get a
standard error, it comes with the solution.

Isobel

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Re: AI-GEOSTATS: Dealing with Universal Kriging

2002-04-09 Thread Isobel Clark

Rubens 

Your approach has been long used in hydrology and
similar fields with much success.

The problem with the standard deviation is that it
does not include the the 'error' on the estimation of
the true drift. To get a composite error you would
either have to 

(a) add your kriging variance to some sort of
classical regression variance to get a composite one;

(b) use a Universal Kriging (or generalised
covariance) approach to estimate the surface with the
drift included.

In our experience, your estimated surface will not
change but your kriging variances will increase
slightly.

Isobel Clark

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