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I have the ASTER version 2 DEM of Cambodia. I want to use it to create 1m contours of Phnom Penh, Cambodia. If anyone has this already please let me know. Now, onto the problems:

  1. I am using ArcGIS so do not have advanced raster processing tools at my disposal such as ER Mapper
  2. The ASTER DEM seems very noisy in Phnom Penh, using the contour tool in ArcGIS simply creates lots of contours around what looks like a field of knolls
  3. Using the focal statistics tool, even with filter sizes up to 30m, does not appear to fix the problem.
  4. I am comparing the output to 10 and 20m contour lines digitised from a topo map. These lines sweep across the city like contour lines should. They are in no way mimicked by the contour lines I have so far been able to generate from the ASTER DEM.

Does anyone have any advice for generating contours from the ASTER raster?

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This gives instructions how to demonise a raster: personalpages.manchester.ac.uk/staff/neil.mitchell/mdenoise. This gives instructions on good settings for denoising ASTER with FW Tools: lists.osgeo.org/pipermail/grass-user/2011-October/062299.html –  ndthl Mar 15 '13 at 5:02
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up vote 4 down vote accepted

Also according to my experience Aster-generated dems are noisy. I usually try to run a low pass filter to smooth the data from the command line window. Anyway, I don't think you will be ever able to obtain good 1m contour lines from Aster (noise, pixel size of 30m, low precision ecc ecc)! I guess you need another source...

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Thanks, I agree. The ASTER data is better for regional scale maps. –  ndthl Feb 1 '12 at 3:23
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