topic Re: Georeferencing a raster overlay using one point, true north, and a bar scale in Data Management Questions https://community.esri.com/t5/data-management-questions/georeferencing-a-raster-overlay-using-one-point/m-p/725387#M41087 <HTML><HEAD></HEAD><BODY><SPAN>You should have a minimum of 4 Control Point to Georeference a raster. Else you should have an existing spatial data (target data), such as Georeferenced raster or a Vector Feature Class of the same location. Take a look at this weblink: </SPAN><A href="http://resources.arcgis.com/en/help/main/10.2/index.html#//009t000000mn000000">http://resources.arcgis.com/en/help/main/10.2/index.html#//009t000000mn000000</A></BODY></HTML> Sun, 02 Mar 2014 09:00:34 GMT NidhinKarthikeyan 2014-03-02T09:00:34Z Georeferencing a raster overlay using one point, true north, and a bar scale https://community.esri.com/t5/data-management-questions/georeferencing-a-raster-overlay-using-one-point/m-p/725386#M41086 <HTML><HEAD></HEAD><BODY><SPAN>I have a bunch of maps I'd like to overlay in ArcMap but almost all of them don't have more than one point I can georeference. These are cave maps and they often have one entrance which I have coordinates for, an indication of true north, and a bar scale. I assume that's enough to get me in the ballpark but I'm not really sure where to start. Any tips would be appreciated.</SPAN></BODY></HTML> Fri, 28 Feb 2014 17:19:43 GMT https://community.esri.com/t5/data-management-questions/georeferencing-a-raster-overlay-using-one-point/m-p/725386#M41086 LukeMazza 2014-02-28T17:19:43Z Re: Georeferencing a raster overlay using one point, true north, and a bar scale https://community.esri.com/t5/data-management-questions/georeferencing-a-raster-overlay-using-one-point/m-p/725387#M41087 <HTML><HEAD></HEAD><BODY><SPAN>You should have a minimum of 4 Control Point to Georeference a raster. Else you should have an existing spatial data (target data), such as Georeferenced raster or a Vector Feature Class of the same location. Take a look at this weblink: </SPAN><A href="http://resources.arcgis.com/en/help/main/10.2/index.html#//009t000000mn000000">http://resources.arcgis.com/en/help/main/10.2/index.html#//009t000000mn000000</A></BODY></HTML> Sun, 02 Mar 2014 09:00:34 GMT https://community.esri.com/t5/data-management-questions/georeferencing-a-raster-overlay-using-one-point/m-p/725387#M41087 NidhinKarthikeyan 2014-03-02T09:00:34Z Re: Georeferencing a raster overlay using one point, true north, and a bar scale https://community.esri.com/t5/data-management-questions/georeferencing-a-raster-overlay-using-one-point/m-p/725388#M41088 <HTML><HEAD></HEAD><BODY><SPAN>You can, carefully, mark 3 other points on your map scaled off from your single origin.</SPAN><BR /><SPAN>Then re-scan and use these for the GCP's to do the image GeoRef.</SPAN><BR /><SPAN>Very do-able.</SPAN><BR /><SPAN>Cheers,</SPAN><BR /><SPAN>Neil</SPAN></BODY></HTML> Tue, 04 Mar 2014 05:07:29 GMT https://community.esri.com/t5/data-management-questions/georeferencing-a-raster-overlay-using-one-point/m-p/725388#M41088 NeilAyres 2014-03-04T05:07:29Z Re: Georeferencing a raster overlay using one point, true north, and a bar scale https://community.esri.com/t5/data-management-questions/georeferencing-a-raster-overlay-using-one-point/m-p/725389#M41089 <HTML><HEAD></HEAD><BODY><SPAN>That's a great idea Neil. Thanks!</SPAN></BODY></HTML> Tue, 04 Mar 2014 12:01:39 GMT https://community.esri.com/t5/data-management-questions/georeferencing-a-raster-overlay-using-one-point/m-p/725389#M41089 LukeMazza 2014-03-04T12:01:39Z