General Information . ... The conference is organized by the Sternberg Astronomical Institute (SAI) of Moscow University and the IAU Working group "Site-testing Instruments" . ... Use of site data in telescope operation and adaptive optics. ... Recent conferences on this subject (2007, 2008) demonstrated great interest of the community, hence the need for a new meeting. ... Unlike previous recent conferences, this meeting will cover all aspects of site monitoring for optical/IR astronomy. ...