[1] School of Civil Engineering and Surveying & Geoinformatics Engineering, Technological Educational Institute of Athens, 2 Agiou Spiridonos Str, Athens,12210, Greece
[2] College of Engineering, University of Kentucky, 265 Raymond Bldg, Lexington,KY,40506-0281, United States
[3] School of Rural & Surveying Engineering, National Technical University of Athens, 9 Hiroon Polytechniou Str, Athens,15780, Greece