To convert the projection of a Surfer GRD file in Didger, the steps are:
- Open Didger 5 and go to File | Import.
- Select the GRD file and click Open.
- In the Assign Coordinate System dialog, choose Projected Coordinates and select the appropriate projection and datum. This is the projection that the grid file is currently in. Click OK.
- Once the file is imported, go to Map | Change Projection.
- Change the projection information to the projection/datum you want, and click OK.
- Now the file is converted and you can export it again (File | Export and export to a DAT file that you can regrid in Surfer) or use Map | Surfer | Grid Data to create a new GRD file.
Updated October 5, 2016