GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 3.3 GNGTS 2024 Automated integraton of AEM data, VES and borehole logs S. Galli 1 , F. Schaars 2 , F. Smits 3,4 , L. Borst 5 , A. Rapit 6 , G. Fiandaca 1 1 The EEM Team for Hydro and eXploraton, Dep. of Earth Sciences A. Desio, Università degli Studi di Milano, Milano (Italy) 2 Artesia Water, 2871 BP Schoonhoven (The Netherlands) 3 Waternet, 1096 AC Amsterdam (The Netherlands) 4 Technical University of Delf, 2628 CD Delf (The Netherlands) 5 PWN, 1991 AS Velserbroek, (The Netherlands) Summary Airborne electromagnetc (AEM) surveys are widely used for hydrogeological applicatons. Target areas for AEM campaigns may present a great deal of ancillary informaton (e.g., resistvity logs, lithology, etc.) and integratng them with AEM data is fundamental. Yet, using this informaton either as a-priori or a-posteriori may bring out conficts between diferent datasets, preventng the ftng of all data. For instance, some borehole drillings may have been logged inaccurately, AEM data may present bias, or data may have been acquired at diferent tmes, with variatons occurring in between. In this study we present a way to integrate AEM data and other types of resistvity data (boreholes electrical logging and vertcal electrical soundings, in this case), through an inversion scheme that identfes automatcally confictng data without preventng the general convergence of the process. In order to do so, we make use of a generalizaton of the minimum support norm, the asymmetric generalized minimum support (AGMS) norm, for defning the data misft in the objectve functon of an iteratve reweighted least squared (IRLS) gauss-newton inversion. The AGMS norm in the data misft caps the weight of non-ftng data points, allowing for the inversion to focus on the data points that can be fted. Outliers are identfed afer the AGMS inversion and excluded, in order to complete the inversion process with a classic L2 misft. We present an applicaton of this method in the Netherlands, on a SkyTEM survey complemented with a vast and open-source database of ashore resistvity logs, as well as vertcal electrical soundings (VES).