I am totally new to GIS software.

I would like to consolidate 205 ASCII GRDs files (the file format of Golden Software's "Surfer") into a single big GRD file or just a big matrix of (about 2400 rows by 2400 columns) I can manipulate within Excel.

Each of the 205 GRDs contain mean windspeed (32 bit float) information of 150x150 cells. I could import these GRDs one by one in Excel but I thought there could be a faster way to do this (I actually have 5 other parameters in this same GRD format).

I was able to put these 205 GRD files in one Arcmap layer using the "Mosaic to New Layer" tool but I didn't find a way to export this layer to a single GRD. I haven't tried the same in QGIS.

Any ideas ?

2 Answers 2


After mosaicing using the Mosaic to New Raster tool, export to ASCII Grid using the Raster to ASCII tool which:

Converts a raster dataset to an ASCII text file representing raster data.


If you have Surfer (or the free Surfer trial version), you can do this in Surfer too and it's really quite easy:

  1. Open Surfer (current version is v18)
  2. Click Grids | Resize | Mosaic.
  3. In the Open Grid(s) dialog, select all 205 grids. You can hold the SHIFT key down, click the first grid and then click the last grid and they'll all be selected.
  4. Click Open.
  5. In the Grid Mosaic dialog, change any options you want (including export file format, if you prefer a list of XYZ points or a Surfer GRD) and just click OK. The single grid is created.

Thanks! Kari

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