Formula in UK and distance in km

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Hi All,

I'm working on prediction analysis using Universal Kriging (UK).
I have two questions.

1) Formula in UK
   My input data are latitude and longitude and wind speed to predict wind
speed at unmeasured points.
   In this case, how do I make the formula in krige function of UK?  For
example, in meuse case, usually, formula is "log(zinc)~sqrt(dist)".
Wind.speed ~ Longitude+Latitude
2) Distance in km
   In semivariance, how do I calculate the distance (h) in km in
semivariogram using longitude (degree) and latitude (degree)?
If you set the CRS such that is.projected reports FALSE, great distances
will be computed assuming long/lat values. For instance:
library(rgdal)
proj4string(meuse) <- CRS("+init=epsg:28992")
meuse.ll = spTransform(meuse, CRS("+init=epsg:4326"))
is.projected(meuse.ll)
[1] FALSE
variogram(log(zinc)~dist+x+y,meuse)[1:3,]
np      dist     gamma dir.hor dir.ver   id
1  57  79.29244 0.0945474       0       0 var1
2 299 163.97367 0.1576838       0       0 var1
3 419 267.36483 0.1837920       0       0 var1

Distances reported are in m.
My data are as follows:

   Longitude Latitude Wind.Speed
1    -87.545   41.757   2.387500
2    -87.669   41.979   2.925000
3    -87.568   41.708   2.137500
4    -87.726   41.739   2.87500
5    -87.558   41.616   3.025000
6    -87.792   41.984   3.242857
7    -87.990   41.668   3.950000
8    -87.753   41.855   1.687500
9    -87.898   42.039   3.687500
10   -87.676  42.062   3.700000

Thanks,

Best Regards,
Jin

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Edzer Pebesma
Institute for Geoinformatics (ifgi), University of M?nster
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http://www.52north.org/geostatistics      e.pebesma at wwu.de