British Geological Survey Global Geomagnetic Model (BGGM) Uncertainties
The paper, SPE/IADC 119851 'Confidence Limits Associated with Values of the Earth's Magnetic Field used for Directional Drilling', described updated uncertainties for use with predicted geomagnetic parameters from the BGGM.
Copies of the paper SPE/IADC 119851 'Confidence Limits Associated with Values of the Earth's Magnetic Field used for Directional Drilling' by Susan Macmillan, British Geological Survey; Allan McKay, Petroleum GeoServices; Steve Grindrod, SPE, Copsegrove Developments Ltd, at the SPE/IADC Drilling Conference in Amsterdam 2009, are available from the SPE.
The results of the study included look-up tables arranged by geographic latitude and longitude for each confidence level. The associated confidence limit tables are avaialble in the files below: