How to create grids (*.grd) from contour lines in Oasis montaj and Target

Objective:
I have a Geosoft map that contains a contour group.  I would like to use this contour group to create a Geosoft grid. (*.grd).

Resolution:

It is not uncommon for Geosoft maps (*.map) to include a geophysical grid overlayed with topographical contours as shown below:

It is possible to extract the contour data from the map to create DTM grid for better visualization.

Step 1: Sample the contour layer to a GDB

1. Open your map and locate the contour layer in the Map Manager Tree. In the example above the contour layer is called CONTOUR_mag_bigrid
2. Right-click the contour layer and select Export to GDB.
3. You will be prompted to enter a database name followed by the New Database popup window.  Be sure there are at least the same amount of lines/groups as the levels of contours in you map.

You should now have a database with X and Y coordinates in the projection of your map and a data channel.  The data channel is the contour values. The contour levels are split into lines in the database.

Step 2: Grid the contour GDB

1. You can now grid the data channel using anyone of the avaiable gridding methods by going to Grid and Image > Gridding > Grid Data.
2. Refine the resolution of the grid using the Cell Size parameter.

Alternative method using an ESRI Shapefile
Some ESRI shapefiles (*.shp) may also be gridded depending on how the data is stored in the file.

1. You can check if useful information is stored in the shp files by importing the shp to a database by going to Map > Import > Import > ArcView Shape File(s)
2. Select your *.shp file and set the “Import data to:” field to New  database.  NOTE: if you also wish to display the *.shp to your map, also select the “Plot map to:” to new or current map. If not, set to Do not import. Click “OK”.
3. Give the input database a name and click “OK”

Once the shapefile has been imported into a Geosoft database (*.gdb), the imported database should have a single line with all the stored data from the shp file. You can now grid the appropriate data channel using the steps outlined above in Step 2: Grid the contour GDB.