Hello All,

My questions are regarding the best way to obtain DEMs for the entire
globe.  I am trying to krige a dataset of global scope.  The dataset has
points at all latitude/longitude intersects and so there are 64,800 sample
points.  The problem that I am having is that the DEMs I have been using are
too large (memory) to be used as R variables.  I also have had trouble
finding a way to download DEMs for the entire globe.

1.  Given the size of my sample dataset: What is the maximum resolution of
DEM that I should be using?  Do I only need values at prediction points or
will higher res yield higher accuracy?

2.  Is there a way to programmatically access DEMs using GDAL or R in
general?  ie. internally or through integration with McIDAS, NetCDF, etc.

3. Do I need to break the DEMs and sample dataset into smaller tiles to
avoid the memory issues?  If so how do I do that in R / GDAL?

Thanks,
Abe

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