
%0 Journal Article
%A Sengpiel, K.P. 
%A Siemon, B. 
%T Examples of 1-D inversion of multifrequency HEM data from 3-D resistivity distributions
%J Exploration Geophysics
%D 1998/06/01
%V 29
%N 2
%P 133-141
%K 
%R https://doi.org/10.1071/EG998133
%U https://www.publish.csiro.au/paper/EG998133 
%X Since 1993 we have been using a program developed by the BGR for the automatic inversion of frequency-domain helicopter electromagnetic (HEM) data into the parameters of a layered half-space. This Marquardt-type inversion procedure uses sounding curves for generating suitable starting models. To better understand the results, model calculations have been carried out using 1-D and 3-D resistivity models to generate synthetic data which were inverted using homogeneous or layered half-space models. Inversion results demonstrate that reliable models can be obtained if sufficient and accurate data are available. In particular, we have shown that the 1-D inversion program provides very useful results even in the presence of lateral changes in resistivity. Several examples of inversion results based on theoretical data and survey data are discussed. 
