Investigation of HEM Forward Modeling Accuracy on Inverse Modeling

Today Helicopter-borne electromagnetic (HEM) data survey play important role for high resolution and fast 3D mapping of resistivity structures within the vast area. The standard method of interpretation of these data is to inverse them frequently. As surveying system is not fixed during the survey, hence noise is accompanying the measured data. To process the measured noisy data they are fed into the several filters to get better data to be used for modeling. During the filtering stage some of signals are also lost. Therefore, it is required to choose modeling techniques that has minimum error and provide accurate subsurface model. In this paper, first the response of the three synthetic layered earth models were calculated by using three different Hankel transform forward modeling methods. Then with adding different percents of random noise to the synthetic data, they were modeled inversely by different methods. The obtained results indicate that the so-called improved Guptasarma-Singh inverse modeling method could provide better responses for all three synthetic models.