Using the hillshade tool (ArcMap 10) on a 30m SRTM raster downloaded from NED the result is the one in the picture. Why are there those crossed lines all over the raster? How could I remove them?
A few thoughts:
- A previous answer correctly recommends resampling during display to smooth out the irregularities in the hillshade. This is primarily used for cartographic effect when you are finishing a map.
- Use the Image Analysis window to run a 5x5 smoothing window over the image
- Find better elevation data. 10 m NED Data is available for the conterminous USA and 3m is available in select areas. I like to download NED data from the National Map
- Finally, to put everything together, consider using advanced overlay methods in Image Analyst, rather than using washed out transparent overlays. Here is a great blog that describes these techniques.