Calculating Aspect from the Raster Calculator

Discussion created by jtholton on Apr 20, 2014
Latest reply on Apr 21, 2014 by jtholton

Does anybody know how to calculate aspect with the Raster Calculator?  I have a 10 meter, GRID, floating point DEM that I downloaded from the USGS. I can easily calculate using the Aspect Geoprocessing tool, but this will not work well for true quantitative analysis. I would like to to be able to generalize aspect by categorizing the aspects into 4 categories, N, S, E, and W.

I would like to convert aspects from 315.1?? to 45?? = N, 45.1?? to 135?? = E, 135.1?? to 225?? = S, 225.1?? to 135 = W. I am pretty certain there is an expression that allows you to perform this transformation but have not been able to find anything on line and am not completely familiar with the raster calculator expressions.

If anybody has experience with this or suggestions on how to go about doing this, I would be extremely grateful.  Thank you so much.


Tom Holton