First results of cirrus clouds properties by means of a pollyxt raman lidar at two measurement sites Kalliopi – Artemis Voudouri, Elina Giannakaki, Mika Komppula and Dimitris Balis EPJ Web Conf., 176 (2018) 05031 Published online: 13 April 2018 DOI: 10.1051/epjconf/201817605031