Öz:Astrogeodetic vertical deflections (VDs) data provide valuable information about the structure of Earth’s gravity field. To obtain astrogeodetic VDs at a point, the astronomic and geodetic coordinates (latitude and longitude) of this point need to be known. Currently, geodetic coordinates are obtained by dual-frequency GNSS receivers, while astronomical coordinates are obtained by the Digital Zenith Camera System (DZCS) or the total station-based QDaedalus system. Although DZCSs provide highly accurate (0.05″–0.1″) VDs data, the DZCSs are usually very expensive to construct and difficult to transport. For these reasons, researchers at ETH Zurich, a leading developer of astrogeodetic instruments, attempted to develop an alternative instrument to the DZCS: the QDaedalus system (accuracy ~0.2″). Unlike the DZCS, the QDaedalus system can be used for geodetic work during daytime. The QDaedalus system consists of a total station, a CCD camera, a mountable meniscus lens, a singlefrequency GNSS receiver and antenna, an interface box, and a laptop. In this paper, the QDaedalus system is presented in detail, and the methods for completing astrogeodetic observations and obtaining astrogeodetic VDs are explained. This paper also reviews all astrogeodetic studies conducted with the QDaedalus system from 2014–2019.