1. Institute for Electromagnetic Sensing of the Environment National Research Council of Italy Naples Italy
2. Institute of Methodologies for Environmental Analysis National Research Council of Italy Tito Italy
3. Université Paris 1 Panthéon‐Sorbonne Paris France
4. Winckelmann‐Institut der Humboldt‐Universität zu Berlin Berlin Germany
5. Dipartimento di Fisica e Scienze della Terra University of Ferrara Ferrara Italy