Create Calibration from File

Use the Gravity > Calibration > Create Calibration from File menu option (GRCALFILE GX) to create a calibration table file from an existing calibration data file that is in some other format.

Format a Calibration Table from a File dialog options

Existing calibration
data file

Specify the name of an existing calibration ASCII data file that may be in any format. The contents of this file will be appended to a template of the required file format.

If you leave this entry blank, or if this file does not exist, you will see a template only.

Instrument ID

Specify the Instrument ID, which is usually just the instrument number (G237 for example). A calibration file will be created using this name with the extension ".csv". If a calibration file exists, you will be asked if you want to replace the file.

Application Notes

Calibration tables are often formatted into two columns of instrument reading and the calibrated milligal equivalent. If you have an existing calibration data in this format, this GX will create a template for a Geosoft compatible file and append the contents of your file. You can then edit your information to the specification of the template.

A calibration file is a standard Geosoft ASCII comma-delimited table file, which contains a "Instrument", "Milligal" and "Scale" column as in the following example:

/ Gravity calibration file: .\105.csv

/ Survey date: 1988/11/14

/ Instrument: G 123

/ Survey database: .\Nov14.gdb

/ Base station database: .\bases2.gdb

/

Instrument, Milligal 

5090.5705, 981200.0819 

5098.0000, 981210.0840 

5110.0000, 981220.0836 

5122.0000, 981230.0833 

5133.0000, 981240.0830 

5144.0000, 981250.0827 

To use a calibration file, the calibration file name must be specified in the survey Processing Parameters (Processing Parameters).