I've recently downloaded SRTM 30m DEM tiles from the USGS Earth Explorer website. The current version of the SRTM 30m DEM has numerous voids that need to be filled. I'd like to hear from the GIS community on the most appropriate methods that can be used to fill the voids without adding addtional systematic errors to the DEM.
I was considering resampling the SRTM 90m DEM using natural neighbours to 30m and using the following to fill the voids within the raw SRTM 30m DEM. Would the following yeild better results than simply filling the voids from the surrounding cells. I'm concerned that some of the voids are pretty large simply filling the voids from the surrounding cells would not represent the actual topographic features correctly.
