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Why are my Contours not matching contours created from using Raster Function Contour Tool?

Question asked by rick.moore_MNDNR on Jan 31, 2020
Latest reply on Jan 31, 2020 by

I am trying to create contours in ArcGIS Pro and I am having issues with outputs from the tool not matching the inputs (from what I can see).  I am starting with a 3 meter DEM and I am creating half foot contours (i know I am not supposed to create half foot contours on a 3 meter DEM but that is not my issue, I believe).  

Original DEM

The process I am using is starting with the output from the Contour function under the Raster Functions in ArcGIS Pro.  The image below is the output from the Raster Function with the defaults.  The contour lines are the output from Contour under Raster Functions.  The DEM below it is also a product of the Contour tool under Raster Functions.  It is the Smoothed Surface Only output.  The two together match up very well and I like the output.

RasterFunction Contour and the Smooth Surface Only output

The problem I have is when I try to run the Contour tool from the Spatial Analyst Toolbox on the Smoothed Surface Only layer (the colored DEM from above), i get Contours that do not match the original DEM or the Smoothed Surface DEM, as seen below.

SpatialAnalyst_Contour and Smoothed Surface Layer

I was hoping for the type of contours that are produced from the Contour tool under Raster Functions.  I would like the vector output similar to the Raster Function Contour but the Contour tool under Spatial Analyst is not producing the same contours.  Am I doing something wrong in these steps?  The Adaptive Filtering of the Raster Function Contour produces a product that i like but I can produce it in a vector format from the Smooth Surface Output from the same tool.