I have a SRTM DEM and I want to create a shaded relief from it. I created the shaded relief in GRASS and the result is very nice, but a little rough becouse the area is near flat and the DEM is 90m in resolution.
What I want is to make the DEM smoother in order to generate a smooth shaded relief. Is there an algorithm or interpolation method to do that?
Here is the shaded relief to get an idea, I want to flatten these small bumps: