topic Re: define projection, drg's in Data Management Questions https://community.esri.com/t5/data-management-questions/define-projection-drg-s/m-p/366166#M20908 <HTML><HEAD></HEAD><BODY><SPAN>Since the files are in sid format now, I would recommend georeferencing the sids rather than trying to adjust the metadata.&nbsp; It sounds like, per your description, that in the conversion process the spatial reference was lost.&nbsp; Is that correct? When you look at the properties of the sid, do you see any custom extents?&nbsp; If you see the same extents from the .tif, then all you will need to do is define the sid's projection with the </SPAN><A href="http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//001700000077000000">Define Projection tool</A><SPAN>.&nbsp; If you see bad extents in the source properties, then I would recommend georeferencing the sid.&nbsp; That way you preserve the compression of the sid and then put it in the correct location.&nbsp; I am including the information on </SPAN><A href="http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Georeferencing_a_raster_dataset/009t000000mq000000/">how to georeference the raster</A><SPAN>, but basically, you should follow these basic steps.</SPAN><BR /><BR /><SPAN>1. Open a new MXD</SPAN><BR /><SPAN>2. Define the coordinate system you want to georeference the raster to</SPAN><BR /><SPAN>3. Add in any corresponding reference data in that same coordinate system</SPAN><BR /><SPAN>4. Georeference the raster by adding control points</SPAN><BR /><SPAN>5. Update the georeferencing</SPAN></BODY></HTML> Tue, 08 May 2012 11:26:32 GMT JeffreySwain 2012-05-08T11:26:32Z define projection, drg's https://community.esri.com/t5/data-management-questions/define-projection-drg-s/m-p/366165#M20907 <HTML><HEAD></HEAD><BODY><SPAN>I have DRG's that have been converted from .tif to SID files and have no metadata associated with them.&nbsp; I am trying to get the files into a proper projection so that I can pull lat/long's off of the image in specific locations. I'm having a hard time figuring out how the files are set up so that I can correctly project them.&nbsp; I believe I need the files in&nbsp; NAD 1927 UTM Zone 5N.&nbsp; If I go back to the metadata listed on the usgs website, the file should have the following spatial extent...</SPAN><BR /><SPAN>Transverse_Mercator: </SPAN><BR /><SPAN>Scale_Factor_at_Central_Meridian: 0.9996 </SPAN><BR /><BR /><SPAN>Longitude_of_Central_Meridian: -153.000 </SPAN><BR /><BR /><SPAN>Latitude_of_Projection_Origin: 0.0 </SPAN><BR /><BR /><SPAN>False_Easting: 500000. </SPAN><BR /><BR /><SPAN>False_Northing: </SPAN><BR /><SPAN>0.0 </SPAN><BR /><BR /><SPAN>The files are too big to upload here but if anyone is able to help I would be happy to send one your way.</SPAN><BR /><SPAN>Thanks,</SPAN><BR /><BR /><SPAN>Aimee</SPAN></BODY></HTML> Mon, 07 May 2012 21:15:03 GMT https://community.esri.com/t5/data-management-questions/define-projection-drg-s/m-p/366165#M20907 AimeeSalstead 2012-05-07T21:15:03Z Re: define projection, drg's https://community.esri.com/t5/data-management-questions/define-projection-drg-s/m-p/366166#M20908 <HTML><HEAD></HEAD><BODY><SPAN>Since the files are in sid format now, I would recommend georeferencing the sids rather than trying to adjust the metadata.&nbsp; It sounds like, per your description, that in the conversion process the spatial reference was lost.&nbsp; Is that correct? When you look at the properties of the sid, do you see any custom extents?&nbsp; If you see the same extents from the .tif, then all you will need to do is define the sid's projection with the </SPAN><A href="http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//001700000077000000">Define Projection tool</A><SPAN>.&nbsp; If you see bad extents in the source properties, then I would recommend georeferencing the sid.&nbsp; That way you preserve the compression of the sid and then put it in the correct location.&nbsp; I am including the information on </SPAN><A href="http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Georeferencing_a_raster_dataset/009t000000mq000000/">how to georeference the raster</A><SPAN>, but basically, you should follow these basic steps.</SPAN><BR /><BR /><SPAN>1. Open a new MXD</SPAN><BR /><SPAN>2. Define the coordinate system you want to georeference the raster to</SPAN><BR /><SPAN>3. Add in any corresponding reference data in that same coordinate system</SPAN><BR /><SPAN>4. Georeference the raster by adding control points</SPAN><BR /><SPAN>5. Update the georeferencing</SPAN></BODY></HTML> Tue, 08 May 2012 11:26:32 GMT https://community.esri.com/t5/data-management-questions/define-projection-drg-s/m-p/366166#M20908 JeffreySwain 2012-05-08T11:26:32Z