Veronica Tofani (a), Ping Lu (b), Filippo Catani (a) & Nicola Casagli (a)
(a) Department of Earth Sciences , University of Firenze, Via La Pira, 4, 51120, Firenze, Italy. E-mail: veronica.tofani@gmail.com
(b) College of Surveying and Geo-Informatics, Tongji University, Siping Road 1239, Shanghai, China.