Airborne geophysical data are processed via standard methods to ensure the response recorded in the data is that due only to the rocks in the ground, thus producing datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data are checked by GA geophysicists using standard methods for assessing quality to ensure that the final data released by GA are fit-for-purpose.Total magnetic intensity data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth's crust. The data are collected on airborne geophysical surveys conducted by Commonwealth, State & NT Governments and the private sector