# Convert .gdf (ICGEM data table) to .tiff

**URL:** <https://forum.generic-mapping-tools.org/t/convert-gdf-icgem-data-table-to-tiff/4897>\
**Category:** Q&A\
**Created:** [May 14, 2024, 5:52pm UTC](https://forum.generic-mapping-tools.org/t/convert-gdf-icgem-data-table-to-tiff/4897 "2024-05-14T17:52:48Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![LauchaCAT](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/lauchacat/32/4190_2.png) [@LauchaCAT](https://forum.generic-mapping-tools.org/u/LauchaCAT)\
**Post date:** [May 14, 2024, 5:52pm UTC](https://forum.generic-mapping-tools.org/t/convert-gdf-icgem-data-table-to-tiff/4897/1 "2024-05-14T17:52:48Z")

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Hello I want to transform a .gdf file to geotiff to open it in Qgis How should I do it?  
Thank you very much

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**Author:** ![Joaquim](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/joaquim/32/16_2.png) [@Joaquim](https://forum.generic-mapping-tools.org/u/Joaquim)\
**Post date:** [May 14, 2024, 6:20pm UTC](https://forum.generic-mapping-tools.org/t/convert-gdf-icgem-data-table-to-tiff/4897/2 "2024-05-14T18:20:14Z")

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> [@LauchaCAT](#):
>
> .gdf file

What is a _.gdf file_?

Anyway, the (maybe) answer lies in `grdconvert`

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<div class="post-metadata">

**Author:** ![LauchaCAT](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/lauchacat/32/4190_2.png) [@LauchaCAT](https://forum.generic-mapping-tools.org/u/LauchaCAT)\
**Post date:** [May 14, 2024, 6:26pm UTC](https://forum.generic-mapping-tools.org/t/convert-gdf-icgem-data-table-to-tiff/4897/3 "2024-05-14T18:26:53Z")

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Yes, I tried that but it does not recognize the format. I downloaded the file from GFZ and it is a dot grid. I can open it with Noted++ for example. The first lines are these:  
generating\_institute gfz-potsdam  
generating\_date 2024/03/11  
product\_type gravity\_field  
body earth  
modelname GSM-2\_2023121-2023151\_GRFO\_UTCSR\_BA01\_0601  
max\_used\_degree 60  
tide\_system tide\_free  
functional gravity\_disturbance  
zero\_degree\_term included  
unit mgal  
refsysname wgs84  
gmrefpot 3.98600441800E+14 m **3/s** 2  
radiusrefpot 6378137.000 m  
flatrefpot 3.352810664747480E-03 (1/298.25722356300)  
omegarefpot 7.29211500000E-05 1/s  
normal\_potential 6.263685171456948E+07 m **2/s** 2  
long\_lat\_unit degree  
latlimit\_north 89.500000000000  
latlimit\_south -89.500000000000  
longlimit\_west -179.50000000000  
longlimit\_east 179.50000000000  
gridstep 1.0000000000000  
latitude\_parallels 180  
longitude\_parallels 360  
number\_of\_gridpoints 64800  
gapvalue 9999.0000  
weighted\_mean -1.4999384E-02 mgal  
maxvalue 1.2760482E+02 mgal  
minvalue -1.1499830E+02 mgal  
signal\_wrms 2.5443690E+01 mgal  
grid\_format long\_lat\_height\_value

```
      longitude latitude h_over_geoid gravity_disturbance
        [deg.] [deg.] [meter] [mgal]

```

end\_of\_head ======================================================  
-179.5000 89.5000 0.00 3.232562610478  
-178.5000 89.5000 0.00 3.253101778178  
-177.5000 89.5000 0.00 3.274010841459  
-176.5000 89.5000 0.00 3.295273624104  
-175.5000 89.5000 0.00 3.316874214221  
-174.5000 89.5000 0.00 3.338796983243  
-173.5000 89.5000 0.00 3.361026602100

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<div class="post-metadata">

**Author:** ![Esteban82](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/esteban82/32/54_2.png) [@Esteban82](https://forum.generic-mapping-tools.org/u/Esteban82)\
**Post date:** [May 14, 2024, 6:29pm UTC](https://forum.generic-mapping-tools.org/t/convert-gdf-icgem-data-table-to-tiff/4897/4 "2024-05-14T18:29:43Z")

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gdf is not a grid. It is a table of data. So, you have to use `grd2xyz`.

Here in this blog I explained (sorry in spanish)

> **[7.3. Mapa Gravimétrico. Anomalía de Bouguer.](https://mapasgeologicos.blogspot.com/2016/10/83-mapa-gravimetrico-anomalias-de.html)**
>
> Blog que explica cómo hacer figuras (mapas, gráficos, perfiles, bloques 3D) con GMT (Generic Mapping Tools) con Windows.

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<div class="post-metadata">

**Author:** ![LauchaCAT](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/lauchacat/32/4190_2.png) [@LauchaCAT](https://forum.generic-mapping-tools.org/u/LauchaCAT)\
**Post date:** [May 15, 2024, 11:28am UTC](https://forum.generic-mapping-tools.org/t/convert-gdf-icgem-data-table-to-tiff/4897/5 "2024-05-15T11:28:25Z")

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Thank you! I´m from Argentina, so spanish is fine for me 😉

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<div class="post-metadata">

**Author:** ![Esteban82](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/esteban82/32/54_2.png) [@Esteban82](https://forum.generic-mapping-tools.org/u/Esteban82)\
**Post date:** [May 15, 2024, 11:52am UTC](https://forum.generic-mapping-tools.org/t/convert-gdf-icgem-data-table-to-tiff/4897/6 "2024-05-15T11:52:34Z")

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Great (me too from Argentina).