1. Institute of Geophysics ETH Zürich Zürich Switzerland
2. Department of Informatics and Telecommunications National and Kapodistrian University of Athens Athens Greece
3. Department of Informatics and Computer Engineering University of West Attica Egaleo Greece
4. Electronics and Photonics Laboratory Department of Physics University of Thessaly Lamia Greece
5. National Observatory of Athens Institute of Geodynamics, Lofos Nimfon, Thission Athens Greece
6. Department of Electrical and Electronics Engineering University of West Attica Egaleo Greece