Creating smooth DEM with constraints

AntonVim — Sat, 28 Sep 2013 18:35:06 GMT

I???m trying to make a DEM of an old mining site. I have point data in a 10*10 meter grid, some lines representing cliffs, and I also have a lake boundary polygon, representing the flooded area of the cavity. When I try to create the DEM with the create TIN or Topo to raster functions, it appears with peaks in the measured height points place. The only way I managed to produce a smooth surface was with the spline tool, but it does not allow the use of barriers. Is there another way to create a smooth surface with those constraints?

Here???s a printscreen of the two surfaces (converted to TIN) in the arcscene (left: spline, right: topo to raster with constrains):
[ATTACH=CONFIG]27850[/ATTACH]

Thank you and apologies for my bad English.

Re: Creating smooth DEM with constraints

XanderBakker — Mon, 30 Sep 2013 06:48:26 GMT

I�??m trying to make a DEM of an old mining site. I have point data in a 10*10 meter grid, some lines representing cliffs, and I also have a lake boundary polygon, representing the flooded area of the cavity. When I try to create the DEM with the create TIN or Topo to raster functions, it appears with peaks in the measured height points place. The only way I managed to produce a smooth surface was with the spline tool, but it does not allow the use of barriers. Is there another way to create a smooth surface with those constraints?

Here�??s a printscreen of the two surfaces (converted to TIN) in the arcscene (left: spline, right: topo to raster with constrains):
[ATTACH=CONFIG]27850[/ATTACH]

Thank you and apologies for my bad English.

Hi Anton,

What you could do is create a raster that contains you constraints and has NoData where there are none. Let's call this raster
"Constraints". In the example below DEM is the DEM created with constraints, in your image on the right.

You could perform the calculation below:

Con ( IsNull ( Constraints ) , FocalStatistics ( DEM , NbrRectangle(3,3,"CELL") , "Mean" , "DATA" ) , DEM )

This will detect those areas with out constraint and calculate the mean elevation in a 3x3 cell neighborhood. The areas with constraints will maintain their value and will not be affected.

Some more reading:
Focal Statistics (Spatial Analyst)
How Focal Statistics works
Conditional evaluation with Con
Is Null (Spatial Analyst)

Kind regards,

Xander

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Creating smooth DEM with constraints

Re: Creating smooth DEM with constraints