Elevation percentile with focal statistics?

Discussion created by sloehr83 on Sep 29, 2010
Latest reply on Jan 28, 2011 by grandearthstyle
Hi all,

I have a DEM and for each cell in the DEM I would like to determine its elevation percentile, i.e. the raking of each cell's elevation relative to all other cells that fall within a circular window of given radius. Conceptually, to obtain the percentile the number of cells that have elevations lower than the centre cell (focal point) is divided by the total number of cells within the circular window.

So, what I would like to work out is how do I return the number of cells that have elevation values below the focal point (ArcGIS 9.3)? I tried to do this with the focal statistics tool, but it does not permit conditional settings and also does not return counts. Can this be done with the focal statistics tool? If not, alternative suggestions on how to approach this would be most welcome.

Thanks for your help.