Strange lines on my hillshade

Discussion created by gustolley on Dec 14, 2011
Latest reply on Dec 15, 2011 by erice-esristaff
I am using Arc 9.3 and have downloaded DEM data from the USGS seamless server for northern New Mexico. When I run the hillshade function after projecting the original DEM from GCS NA 1983 to UTM NAD 1983 Zone 13, I get these strange lines all over my hillshade that have a skewed grid pattern. They are all over and a quite closely spaced.

The hill shade looks fine without the transformation when I use the correct z factor, so I am pretty sure it is not the data itself. I am not using any geographic transformation during the conversion, so that may be it. Any recommendations or advice would be appreciated.