Objective function analysis for electric soundings (VES), transient electromagnetic soundings (TEM) and joint inversion VES/TEM

Author(s)

Bortolozo, Cassiano Antonio ^[1] ; Bokhonok, Oleg ^{[1, 2]} ; Porsani, Jorge Luis ^[1] ; Monteiro dos Santos, Fernando Acacio ^[3] ; Diogo, Liliana Alcazar ^[1] ; Slob, Evert ^[4]

Affiliation

^[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer IAG, Dept Geofis, Sao Paulo - Brazil

^[2] Univ Catolica Santos UNISANTOS, Inst Pesquisas Cient & Tecnol Ipeci, Santos - Brazil

^[3] Univ Lisbon, Inst Don Luiz, Lisbon - Portugal

^[4] Delft Univ Technol, Dept Geotechnol, Delft - Netherlands

• Document type: Journal article
• Source: JOURNAL OF APPLIED GEOPHYSICS; v. 146, p. 120-137, NOV 2017.
• Web of Science Citations: 0

Abstract

Ambiguities in geophysical inversion results are always present. How these ambiguities appear in most cases open to interpretation. It is interesting to investigate ambiguities with regard to the parameters of the models under study. Residual Function Dispersion Map (RFDM) can be used to differentiate between global ambiguities and local minima in the objective function. We apply RFDM to Vertical Electrical Sounding (VES) and TEM Sounding inversion results. Through topographic analysis of the objective function we evaluate the advantages and limitations of electrical sounding data compared with TEM sounding data, and the benefits of joint inversion in comparison with the individual methods. The RFDM analysis proved to be a very interesting tool for understanding the joint inversion method of VES/TEM. Also the advantage of the applicability of the RFDM analyses in real data is explored in this paper to demonstrate not only how the objective function of real data behaves but the applicability of the RFDM approach in real cases. With the analysis of the results, it is possible to understand how the joint inversion can reduce the ambiguity of the methods. (C) 2017 Published by Elsevier B.V. (AU)

• FAPESP's process: 09/08466-3 - Geoelectric characterization of fractured aquifers in basalt in the region of Bebedouro, SP, by using joint inversion of SEVs and TDEM soundings
• Grantee: Jorge Luís Porsani
• Support Opportunities: Regular Research Grants
• FAPESP's process: 11/06404-0 - 1D and 2D joint inversion of resistivity and TDEM data for hydrogeology studies in the Paraná basin
• Grantee: Cassiano Antonio Bortolozo
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 12/15338-4 - Mapping of fractured aquifers in basalt of the Serra Geral Formation in northwestern region of the São Paulo State, using 1D and 2D joint inversion of resistivity data (VES and ES) and time domain electromagnetic soundings (TDEM)
• Grantee: Jorge Luís Porsani
• Support Opportunities: Regular Research Grants