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GEOSTATS: optimal sampling design

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  • GGP95RDS@sheffield.ac.uk
    Hello, Can anyone out there point me towards software I can use to calculate the kriged estimation mean and kriged estimation variance so that I generate
    Message 1 of 2 , Mar 1 4:04 AM
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      Hello,

      Can anyone out there point me towards software I can use to calculate
      the kriged estimation mean and kriged estimation variance so that I
      generate graphs of number of observations within an isolated region
      against standard error (as in McBratney and Webster 1983; Webster &
      Oliver 1990: 272-282)?

      I want to use the kriged estimation variance to prescribe optimal
      (soil) sampling designs for my study areas based on sampling on
      regular rectangular grids.

      I have 8 data-sets for which I have modelled the experimental
      variograms and have produced kriged contour map outputs using the
      variogram parameterson Surfer 6.01. However, I cannot see any way of
      calculating kriged variance and means using this software.

      Looking forward to some help...

      Many thanks,

      Richard D Smith
      Sheffield Centre for International Drylands Research (SCIDR)
      Department of Geography
      University of Sheffield
      Winter Street
      Sheffield S10 2TN
      UK

      email: ggp95rds@...
      fax: (44)(0)114-2797912
      voice (44)(0)114-2227930

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    • Heinz Burger
      ... Hello Richard, it is well known that SURFER don t handle kriging errors (yet). A simple trick for getting an error map: Take GEOEAS and transfer the output
      Message 2 of 2 , Mar 3 12:48 AM
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        GGP95RDS@... wrote:

        > Hello,
        >
        > Can anyone out there point me towards software I can use to calculate
        > the kriged estimation mean and kriged estimation variance so that I
        > generate graphs of number of observations within an isolated region
        > against standard error (as in McBratney and Webster 1983; Webster &
        > Oliver 1990: 272-282)?
        >
        > I want to use the kriged estimation variance to prescribe optimal
        > (soil) sampling designs for my study areas based on sampling on
        > regular rectangular grids.
        >
        > I have 8 data-sets for which I have modelled the experimental
        > variograms and have produced kriged contour map outputs using the
        > variogram parameterson Surfer 6.01. However, I cannot see any way of
        > calculating kriged variance and means using this software.

        Hello Richard,

        it is well known that SURFER don't handle kriging errors (yet). A simple
        trick
        for getting an error map: Take GEOEAS and transfer the output to
        Surfer. Use "nearest neigbour"-method for gridding with search-radius
        smaller than grid distance. This will reproduce exactly the kriging results
        - including errors.

        The other point is that you can't get the global estimation variance by this
        way.
        Since you have got data on a regular grid, you should use the "combination
        of elementary
        errors" (Journel & Huijbregts, Mining Geostatistics, Chapt. V.C).
        For irregular sample distribution see our on-line paper on "Geostatistics
        and the Polygonal
        Method" including a (German)VB3.0-program. (See my web-page: News).

        Good luck!

        Heinz Burger

        --
        *****************************************************
        Dr. Heinz Burger
        Freie Universitaet Berlin
        - Geoinformatik -
        Malteserstr. 74-100
        12249 BERLIN, Germany
        e-mail: hburger@...-berlin.de
        Web-Seite: http://userpage.fu-berlin.de/~hburger/hb/
        ****************************************************



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