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Creating Contours from Elevation Models

October 01 2009 | 0 comments
Categories: ArcGIS Methods, Map Data

I believe Charlie Frye wrote a paper on creating contours from DEMs.
In that article he speaks of "smoothing the DEM using the FOCAL STATISTICS tool.
In using the tool, he says to set the statistics type to median.
However, when I try to do that, the type median is not visible. Does the raster need to be in a certain format? I am using a continuous floating point
ESRI grid. I know you are not tech support, but I would appreciate it if you could give me some guidance in this.
Thanks in advance.

Mapping Center Answer:

I think it had more to do with the version of the software--I had noticed that as well, I think in 9.2.  Then I tried recently  and median was back.  When I did not have it available, I used Mean, which works almost as well (you'd have to look hard at the pixels to tell a difference.  Mainly I prefer that actual measured elevation values remain in the elevation data.

On trick to having this work better with Mean, or Median, is to first run the Filter tool, with the Lower option.

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