I am trying to use a DEM with 1 meter vertical intervals to generate a second DEM in which each pixel is assigned a value interpolated from surrounding pixel values. I know that this is, in general, where the IDW tool is applied. However, I am hitting an issue where slope is overestimated at boundaries between areas of different pixel values and away from boundaries when using IDW and all other interpolation tools that I know of. I know that the site modeled by the DEM actually has a fairly uniform slope (except one area of a hill's toeslope), without true stair step topography as estimated by IDW, but I do no know how to capture this in a new DEM.
Below is an image of DEM. Z values are meters above sea level, from 72 to 84. The raster displayed is 'estes_dem_2,' highlighted to the left.
Below is an image of a DEM generated using the IDW tool, with power=2, and a fixed search radius of 1000 meters. Note that change in interpolated pixel values is still very rapid at boundaries between prior regions of static pixel value. Ideally, elevation will decrease/increase evenly across in the new DEM across the width of any region of shared pixel values in the original DEM. The raster displayed is 'Idw_shp14.' Note the rudimentary scale bar to the left of the raster.
How can I accomplish this in ArcMap or another software with spatial capabilities like QGIS or R?
