Calculate area of raster cells

P.S. The solution I just posted assumes the earth is a sphere, not an
ellipsoid (which would be more accurate).
These are projected, not geographical coordinates, unfortunately. The case
for calculating areas on an ellipsoid is much harder, I'm afraid.

Roger

On Wed, 28 Apr 2010, Paul Hiemstra wrote:

Tim Erbrecht wrote:
Dear all,

having data in a SpatialGridDataFrame with geographic coordinates, is
there a simple method to calculate the spatial area for each cell? I wasn't
able to find anything in the list archives ...

Thanks and best regards

Tim

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with the meuse dataset:

library(sp)
data(meuse.grid)
gridded(meuse.grid) = ~x+y
fullgrid(meuse.grid) = TRUE
bla = gridparameters(meuse.grid)
area = bla$cellsize[1] * bla$cellsize[2]
area
These are projected, not geographical coordinates, unfortunately. The case
for calculating areas on an ellipsoid is much harder, I'm afraid.

Roger

cheers,
Paul

--
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no

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Calculate area of raster cells

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