dukill Posted March 21, 2012 Posted March 21, 2012 I just want to start out by saying I know a little bit about cad but I do not know a whole lot about plotting corrdinates. My issue is as follows. I have about 40 gps corrdinates that I took with Droid2Cad which are recorded as lat, long, and alt. The points can be exported to .dxf and .kml(google earth). I have exported them to both and it looks like google earth plots them correct but I have issues with the .dxf file. I have a .dwg site plan of an agriculture site from a engineering firm that seems to be drawn at 1:1. When I go to overlay the points on the site plan the points end up way off off the site plan. I dont know if I need to scale the .dxf or what. The points seem to be in the right configuration but they dont land anywhere close to the right spots. When I overlayed the points on the .dwg, I selected all the points, copied with a base point on a point that I knew the corresponding point on the .dwg, and pasted that point to the point on the .dwg. I dont know if I did a good enough job explaining this but I would appreciate any help anyone can give me. If you need more info or clarification please let me know. Thank you for your time. Aaron Daniels Quote
dukill Posted March 21, 2012 Author Posted March 21, 2012 Ok. I think I might have figured something out but I dont know how to fix it. It looks like the .dwg site drawing was drawn unitless and each unit is to represent 1'. On the other hand my gps coordinates(.dxf) are ploted unitless in inches so each unit is 1". So when I overlay the coordinates on the site plan the points are 12x the distance they are supposed to be. Can anyone tell me an easy way to scale the gps corrdinates in model space? Quote
Murph_map Posted March 22, 2012 Posted March 22, 2012 Ok. I think I might have figured something out but I dont know how to fix it. It looks like the .dwg site drawing was drawn unitless and each unit is to represent 1'. On the other hand my gps coordinates(.dxf) are ploted unitless in inches so each unit is 1". So when I overlay the coordinates on the site plan the points are 12x the distance they are supposed to be. Can anyone tell me an easy way to scale the gps corrdinates in model space? Your GPS points are Lat/Lon units. The distance varies between points varies depending where you are at on the earth. Close to the poles one unit may be inches while at the equator it may be miles. AutoCAD Civil 3d or Map3D can convert the points to a state plane (feet) coordinate system. If you can get the points to a txt or excel format there is a program called Corpscon that will convert them. Quote
BIGAL Posted March 23, 2012 Posted March 23, 2012 I would move your DWG Site to the GPS co-ords not the other way this way you have a plan with real world co-ords and anyone can use. Quote
Murph_map Posted March 24, 2012 Posted March 24, 2012 I would move your DWG Site to the GPS co-ords not the other way this way you have a plan with real world co-ords and anyone can use. Agree as long as their is a disclaimer in the dwg stating it was located with a Droid cell phone or mobile device and accuracy may be within 10 feet. Quote
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