topic Re: 30X30 DEM in ArcGIS Spatial Analyst Questions https://community.esri.com/t5/arcgis-spatial-analyst-questions/30x30-dem/m-p/372818#M5228 <HTML><HEAD></HEAD><BODY><P>Use mosaic to new raster tool and Set output cell size to 30 while mosaicing the DEM's. </P></BODY></HTML> Fri, 13 Feb 2015 13:16:33 GMT KishorGhatage 2015-02-13T13:16:33Z 30X30 DEM https://community.esri.com/t5/arcgis-spatial-analyst-questions/30x30-dem/m-p/372817#M5227 <HTML><HEAD></HEAD><BODY><P>Hello,,, </P><P></P><P>I have just downloaded a 30x30m DEM from&nbsp; ASTER GDEM. However, after I mosaic it and open in in Arcmap, I found it to be actually 0.00027777x0.00027777m resolution and could not get a realstic feature (vertical lines) when I export and view it in HEC-RAS.Your usual and kind helps please.</P><P></P><P>Yared.</P></BODY></HTML> Fri, 13 Feb 2015 13:08:49 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/30x30-dem/m-p/372817#M5227 YaredMichael 2015-02-13T13:08:49Z Re: 30X30 DEM https://community.esri.com/t5/arcgis-spatial-analyst-questions/30x30-dem/m-p/372818#M5228 <HTML><HEAD></HEAD><BODY><P>Use mosaic to new raster tool and Set output cell size to 30 while mosaicing the DEM's. </P></BODY></HTML> Fri, 13 Feb 2015 13:16:33 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/30x30-dem/m-p/372818#M5228 KishorGhatage 2015-02-13T13:16:33Z Re: 30X30 DEM https://community.esri.com/t5/arcgis-spatial-analyst-questions/30x30-dem/m-p/372819#M5229 <HTML><HEAD></HEAD><BODY><P>your coordinates appear to be in decimal degrees.&nbsp; This can be confirmed by looking at the layer's properties.&nbsp; If they appear to be in the realm of decimal degree coordinates, then you need to project the raster to your desired projection (ie UTM etc etc) using the <A href="http://resources.arcgis.com/en/help/main/10.2/index.html#/Project_Raster/00170000007q000000/">Project Raster</A> tool in ArcToolbox</P></BODY></HTML> Fri, 13 Feb 2015 13:23:16 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/30x30-dem/m-p/372819#M5229 DanPatterson_Retired 2015-02-13T13:23:16Z