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I have downloaded SRTM 1 ArcSec and processed it to retrieve topographic attributes. Prior to this, I have used 'fill' tool in ArcGIS as a pre processing step. Following is snapshot of clipped DEM; Downloaded and Clipped SRTM-1 Arc Sec

The resultant hillshade raster shows linear features/strips visible in the following tile; hillshade from processed DEM

Despite of removing sinks using 'fill' tool, these imperfections are resulted in unreliable derivatives from it like slope, aspect, curvature, TWi etc. The following tile clearly indicates imperfections in derived 'Curvature' raster.

Curvature

If any one has experienced same issues, can you let me know how to remove these imperfections in any GIS software?

  • Did you reproject it? – aldo_tapia Nov 19 '16 at 10:29
  • Yes, I have reprojected it. – Ben Nov 19 '16 at 10:51
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    Pixels suffer some distortion when are reprojected. Also, resampling method is important, nearest neighbor will generate those lines; cubic convolution problems in river box of DEMs; bilinear interpolation seems to be the appropriate for DEM. But, I don't recommend you to reproject your DEM, process it in original CRS and reproject the final products. Take a look of this – aldo_tapia Nov 19 '16 at 11:01
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    You should select the Bilinear Or Cubic Convolution resampling when projecting the DEM. Do not use nearest neighbor resampling because it will create the lines you see in your image – ahmadhanb Nov 19 '16 at 11:03
  • Thank you for the guidance, @aldo_tapia and ahmadhanb, I will proceed through original CRS and also check whether other interpolation techniques yield acceptable results or not. – Ben Nov 19 '16 at 11:32

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