Change the map coordinates of a DXF file in Surfer

Option 1: Add the DXF as a Base map then assign a new coordinate system and export.

1. Click Home | New Map | Base | Base, select the DXF file, and click Open to load the DXF file as a base map.
2. In the Contents window, select the DXF Base(vector) layer. 
3. In the Properties window, select the Coordinate System tab.
   • If there is a coordinate system listed, continue to Step 4
   • If it says Unreferenced Local System, click the Set button.
     1. In the Assign Coordinate System dialog, choose the source coordinate system of your DXF file.
     2. Click OK.
4. In the Contents window, select the Map frame that contains your Base(vector) layer.
5. In the Properties window, select the Coordinate System tab.
6. Click the Change button.
7. In the Assign Coordinate System dialog, choose a new coordinate system for your DXF.
8. Click OK.
9. In the Contents window, uncheck the all axes in the Map frame.
10. Choose File | Export, give the file a new name, choose to export it as an AutoCAD DXF Drawing file, and click Save.
11. In the Export Options dialog, ensure the Scaling source is set to Map.
12. Click OK.

Option 2: Use the page coordinates of two calibration points with known map coordinates on your map to create a new DXF with the changed coordinates.

1. Click Home | Insert | Graphic, select the DXF file and click Open to load the DXF file and display it without axes or map coordinates.
2. Zoom in on the first known point and write down the XY page coordinates from the status bar at the bottom of the plot window.
3. Zoom out, scroll to the next point and write down the page coordinates for the second known point.
4. Choose File | Export, give the file a new name, choose to export it as an AutoCAD DXF Drawing file, and click Save.
5. In the Export Options dialog, on the Scaling page, enter the two sets of page coordinates in the Source Rectangle boxes.
6. Enter the corresponding map coordinates under the File Rectangle boxes.
7. Although the dialogue box prompts for the Lower Left and Upper Right points, you may enter any two map points.
8. Click OK to create the new DXF file.
9. To load the file into Surfer with map coordinates, click Home | New  Map | Base, select the DXF file and click Open.

Updated November 2021