Dear Enrico, I see 2 ways to proceed: 1. use indicator kriging after a soft indicator coding of all your observations (see Saito, H. and P. Goovaerts. 2002. Accounting for measurement error in uncertainty modeling and decision making using indicator kriging and p-field simulation: Application to a dioxin contaminated site. *Environmetrics*, 13:555-567. <http://home.comcast.net/%7Epgoovaerts/ENV01.pdf> for an example). 2. use kriging with nonsystematic errors (see book by Chiles and Delfiner page 210). This simply amounts at adding a measurement variance term to each diagonal element of the kriging matrix (same principle is also used in Poisson kriging where we manipulate rate data with different level of reliability based on the size of the underlying population).
Cheers, Pierre On Mon, Sep 28, 2009 at 8:54 AM, Enrico Guastaldi < [email protected]> wrote: > Dear list members, > I'm looking for some kind of interpolation for values of an environmental > variable which has been measured together the measurement errors, for > instance a measure is 45ppm +or- 10.7ppm, another one is 10ppm +or- 3ppm, > and so on. In practice, measures and measurement errors are two independent > variable. > I could use some kind of kriging, however I exactly know the magnitude of > each error at every sampled location, i.e. the value plus or minus the error > gave me by the laboratory. > Could anyone tell me what kind of function should I use for handling this > problem? > It should be nice some R package, of course, but I need to understand the > background theory. > Thanks in advance, > Regards, > > Enrico Guastaldi > -- Pierre Goovaerts Chief Scientist at BioMedware Inc. 516 North State Street Ann Arbor, MI 48104 Voice: (734) 913-1098 (ext. 8) Fax: (734) 913-2201 Courtesy Associate Professor, University of Florida Geostatistician, Computer Sciences Corporation President, PGeostat LLC 710 Ridgemont Lane Ann Arbor, MI 48103 Voice: (734) 668-9900 Fax: (734) 668-7788 http://goovaerts.pierre.googlepages.com/
