National and Kapodistrian University of Athens - Department of Informatics and Telecommunications, National and Kapodistrian University of Athens - Department of Informatics and Telecommunications, National and Kapodistrian University of Athens - Department of Informatics and Telecommunications, National and Kapodistrian University of Athens - Department of Informatics and Telecommunications, National and Kapodistrian University of Athens - Department of Informatics and Telecommunications, National Observatory of Athens, National Observatory of Athens, Harokopeio University of Athens, National and Kapodistrian University of Athens - Department of Informatics and Telecommunications and National Observatory of Athens