topic Strange lines on my hillshade in Data Management Questions https://community.esri.com/t5/data-management-questions/strange-lines-on-my-hillshade/m-p/613859#M34622 <HTML><HEAD></HEAD><BODY><SPAN>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. </SPAN><BR /><BR /><SPAN>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.</SPAN><BR /><BR /><SPAN>Thanks.</SPAN></BODY></HTML> Wed, 14 Dec 2011 23:45:01 GMT GusTolley 2011-12-14T23:45:01Z Strange lines on my hillshade https://community.esri.com/t5/data-management-questions/strange-lines-on-my-hillshade/m-p/613859#M34622 <HTML><HEAD></HEAD><BODY><SPAN>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. </SPAN><BR /><BR /><SPAN>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.</SPAN><BR /><BR /><SPAN>Thanks.</SPAN></BODY></HTML> Wed, 14 Dec 2011 23:45:01 GMT https://community.esri.com/t5/data-management-questions/strange-lines-on-my-hillshade/m-p/613859#M34622 GusTolley 2011-12-14T23:45:01Z Re: Strange lines on my hillshade https://community.esri.com/t5/data-management-questions/strange-lines-on-my-hillshade/m-p/613860#M34623 <HTML><HEAD></HEAD><BODY><SPAN>Greetings,</SPAN><BR /><BR /><SPAN>Without a screenshot to go off of, it sounds like you may have used Nearest resampling when you projected the data.&nbsp; Try projecting the original file again, but make sure you set the resampling to Bilinear.&nbsp; </SPAN><BR /><BR /><SPAN>Regards,</SPAN><BR /><SPAN>Eric</SPAN></BODY></HTML> Thu, 15 Dec 2011 14:22:05 GMT https://community.esri.com/t5/data-management-questions/strange-lines-on-my-hillshade/m-p/613860#M34623 EricRice 2011-12-15T14:22:05Z