Gaussian Pyramid Downsample

On Raster GIS, Downsampling menu

For the current DEM

• Saves the original DEM in a new subdirectory under c:\mapdata\multigrid
• For 5 iterations
  • Filters the DEM with a 5 term square gaussian filter
  • Thins the DEM by the factor of two (data spacing becomes twice as large, file size one quarter of the starting grid)
  • Saves the new DEM

This could be used to take a 1 m lidar DTM, and create generalized grids at 2, 4, 8, 16, and 32 meters.   Alternatively you could create the lower resolution grids directly from the point cloud.

For a 0.4" grid, you could create generalized grids at 0.8, 1.6, 3.2, and 6.4 arc seconds

Reference:

• T. Behrens, K. Schmidt, R.A. MacMillan, R.A. Viscarra Rossel, 2018, Multiscale contextual spatial modelling with the Gaussian scale space:  Geoderma, Volume 310, p 128-137, https://doi.org/10.1016/j.geoderma.2017.09.015 .

Last revision 8/19/2021