Hello again,
As I mentioned, I am compiling corn yield data for the grain belt US based on county-wide data for about 14 states. Eventually I will need to plot these data to analyze yield spatial distribution. So I need to be able to assign these county production values to some location, probably the geographic center of each county.
One of the goals is to calculate a center of mass for production. The region of interest spans:
Lat: 35N to 49N
Lon: -104 to -80
The question is how to choose a projection that will allow me to calculate a reasonable (yet to be determined what will be considered reasonable) estimate of center of mass. I am considering Albers Equal Area, Equidistant Conic, Azimuthal Equidistant, and Two-Point Equidistant. (I am using GRASS, and I think TPE is not supported).
Thanks again for your help.
Martin