Michael,
Kriging with External Drift, as implemented in the GSLIB set of programs
(Deutsch & Journel) is distinct from Universal Kriging, in that the
"External Drift" is intended to be defined by a secondary variable that you,
the user, "believe" incorporates some information of relevance to the
So are you saying that the external drift variable in the matrix is just the
magnitude of the the drift variable at that point?
ie :
3 point kriging
s = drift variable
[ k11 k12 k13 1 s1 ] [ l1 ] [ k01 ]
[ k21 k22 k23 1 s2 ] [ l2 ] [ k02 ]
[ k31 k32 k33 1 s3 ] [ l3 ] = [ k03 ]
[ 1 1
Michael
Maybe we have not made this clear.
Universal kriging is a two stage process.
(1) Fit a trend (global) or local trends and calculate
the residuals. From these residuals you obtain a
de-trended (drift-less) semi-variogram.
(2) Using the semi-variogram derived in (1) together
with the e
On Thursday, December 6, 2001, at 04:12 AM, Michael Dennis wrote:
>
> I don't think this is right but if you can explain to me how the Drift
> is
> actually applied in laymans terms it would be greatly appreciated. Also
> when you do kriging with external drift do you have to model a
> variog
Thanks for the info. I don't mind you plugging your book, that was one of
the questions I asked : What is a good reference on this subject.
See this is where I start getting confused with terminology. I'm talking
about KED (Kriging with External Drift) and then you start talking about
Universal
Title: RE: AI-GEOSTATS: Kriging with External Drift
Thanks
for clearing that up for me. I get confused with the terminology
sometimes. I'll see if I can get a copy of the book you mention to look at
to see if it helps me out.
You
say that KED uses a shape function for the "Drift" data.
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Hello Michael!
What you are describing is kriging in the presence of a drift,
e.g. kriging of a (single) nonstationary RV. You may proceed as
described in your email or use universal kriging (UK) for that.
External drift refers to a second variable which may be used
in order to improve estimatio
