Correct structural index defined by base level estimates in Euler deconvolution

The main goal of Euler deconvolution is to define the source nature and its depth position. Besides that, it estimates base level of the data and horizontal positions of the sources. To define the correct structural index most authors take advantage of the clustering in depth estimates. Some authors assume constant, linear or nonlinear base levels in their formulation, thus they estimate or eliminate this parameter from their analysis. With a tentative structural index, we take advantage of base level clustering when the correct structural index is used. We modeled three bodies with different structural indices and show that minimum variation of depth is sufficient to indicate the correct structural index when no interfering anomalies are present. In the presence of interfering anomalies, the minimum variation of base level estimates indicates the correct structural index. We simulated constant and nonlinear base levels in our tests. Application to a real data set shows that nonlinear base level is present possibly due to interfering anomalies. These results are valid independent of geomagnetic field incidence.