Use the GRD Surfer 6 Text Grid formats to add information to the bottom of the grid (GRD) file. Surfer does not use any information after the last Z value in the GRD file.
One use for this procedure is to add a text version of the gridding report to the end of the file. Surfer does not read this information, but you can view the information in a text editor.
GRD Surfer 6 Text Grid
DSAA nCols nRows xMin xMax yMin yMax zMin zMax z11 z21 z31 ... ... znCols znRows <additional text or data>
For more information on the Surfer 6 Text Grid file format, please see here.
Updated October 16, 2018