Using 10.0 I've got a raster of a fairly flat area and i'm trying to calculate the slope. Values for elevation are accurate and I am expecting slope values no more than 5 degrees over the raster.
After running the Slope (3D Analyst) I am getting slope values of 89 - 85 degrees and can't figure out why.
According to http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?TopicName=Calculating_slope the slope (θ) should be from the horizontal to the grade, but it looks like its being calculated from the zenith to the grade (90-θ off of what i'm expecting).
Any ideas on what I'm doing wrong?