I need to compute focal statistics (sum, mean etc.) for raster data spanning the whole globe. I want to use a constant radius e.g. 100km around each cell.
However the data are geographic (WGS84), so setting a radius in map units will result in the geodesic size of this radius changing with latitude.
I've written a little python script to crunch the numbers by re-calculating the filter width with every latitude to keep the geodesic radius constant, but this is slow & a bit inelegant.
Can anyone suggest a better way of doing this in ArcGIS Desktop?