AI-GEOSTATS: KRIGING EVALUATION

[Farina, Fabrizio/MIL]

Hi All,

   I'm currently trying to krig Oxygen Concentration Data starting from only about 
15 data points. Obviously, interpolation results are not reliable in the outer part of 
the region I'm working on, while they're pretty good in the inner part, where most of 
the data points are located. I've been told that I might discard the outer data based 
on the variance map, basically saying something like if the krig variance exceeds the 
value X, then I decide not do consider the results I've obtained as valid. I'm not 
sure this approach is correct and, if so, how to choose the variance threshold? Any 
suggestion?

Many thanks in advance to anyone who can help me.

Best regards,

  Fabrizio Farina



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Re: AI-GEOSTATS: KRIGING EVALUATION

[Isobel Clark]

Fabrizio 

If you want to limit your estimates by kriging
variance, the obvious place to stop would be where the
kriging variance becomes equal to the total sill on
your semi-variogram (if you have one) or to the
estimated population variance for your sample values.

A kriging variance above this value, basically, says
that your estimate is a worse estimator than just
using the population mean.

Isobel Clark
http://geoecosse.bizland.com/news.html

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