How To: Add custom formulae for Gravity latitude and free-air corrections

Problem/Symptom:
You want to use your own formula for the latitude or free-air correction.

Environment:
For use with the Gravity and Terrain Correction extension. Applies to versions 6.x, 7.0 and onwards.

Resolution:

1. You will find the formula files for the latitude correction (Gravity_Formulas.lst) and free air correction (Gravity_Free_Air.lst) in C:\Program Files\Geosoft\Oasis montaj\user\etc.

NOTE: The Gravity_Formulas.lst and Gravity_Free_Air.lst files may not appear in the \user\etc directory above. If they do not, then you did not run the Processing Parameters when first setting up your project. You can try running the Processing Parameters GX at this point to create the two LST files, but if this does not work, simply create a new empty project, load the Gravity.omn file, and then run the Processing Parameters GX. The two LST files will now be created and you can work with them.

2. Open the file in a text editor, and add your custom formula following the format of an existing generic formula. Save the file.

3. When you open the Gravity > Processing Parameters dialog, your formula should now be selectable under the relevant field.

Note - Users are unable to change the formula used for Bouguer calculations.