
%0 Journal Article
%A Reeves, C.V. 
%T Limitations imposed by geomagnetic variations on high quality aeromagnetic surveys
%J Exploration Geophysics
%D 1993/06/01
%V 24
%N 2
%P 115-116
%K 
%R https://doi.org/10.1071/EG993115
%U https://www.publish.csiro.au/paper/EG993115 
%X The accuracy and sensitivity with which aeromagnetic anomaly data may be collected ? and presented as images for those who seek to maximise the representation of the geological information ? is limited by the thoroughness with which temporal variations are removed from the recorded total field data. Three processes are currently used consecutively to eliminate time-variations: base station subtraction, tie-line levelling and micro-levelling. Of these, the first two involve assumptions that are not entirely justifiable and the third is essentially an arbitrary filtering process. On profile data with a noise envelope of no more than ±0.1 nT, even the third process involves adjustments that can be many times larger than other uncertainties in the data. 
