# units for spatial range in stvariogram gstat

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## units for spatial range in stvariogram gstat

Dear All,
I have question concerning the unit of measurement for the range parameter in the fit.stvariogram in gstat, i have fitted the following spatio temporal variogram for data on monthly averages pf pm10 and the longitude and latitude are in decimel format

> pm10_sp
SpatialPoints:
longitude latitude
1     30.92500 29.95300
61    31.36000 30.26000
121   31.33300 29.84720
and this is the commands for fitting the variogram
> varpm10 <- variogramST(lnpm10only~1,data=lnpm10_stfdf,cutoff=0.8,assumeRegular=T,na.omit=T)
> plot(varpm10,map=F)
> sumMetric <- vgmST("sumMetric", space = vgm(psill=5,"Mat", range=50, nugget=0),time = vgm(psill=500,"Mat", range=50, nugget=0,kappa=0.3), joint = vgm(psill=10,"Mat", range=100, nugget=1), stAni=200)
> sumMetric_Vgm <- fit.StVariogram(varpm10, sumMetric, method="L-BFGS-B",lower=pars.l,upper=pars.u)
> plot(varpm10,sumMetric_Vgm,map=F)

> extractPar(sumMetric_Vgm)
sill.s      range.s     nugget.s       sill.t      range.t     nugget.t
1.73598444  50.63845035   0.03212857   0.01570379  49.99811448   0.00000000
sill.st     range.st    nugget.st         anis
0.00000000 100.00004052   0.09151787 200.00000000

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now i want to know the units for these parameters in order to be able to interpret it for example is it in km or m.

I really appreciate any help that I deeply need

Best Regards
Sara

 Faculty of Economics & Political ScienceCairo University

Tel:(202)35728055-(202)35728116-(202)35736608-(202)35736605
Fax:(202)35711020

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