The Space Geodesy Group at KASI focuses on global geodesy, that is, detection of the tiny variations in Earth’s shape and rotation, using primary space geodetic techniques and instruments such as the Global Navigation Satellite System (GNSS), very long baseline interferometry (VLBI), and satellite laser ranging (SLR). This research field covers a wide range of precise positioning techniques, from determination of reference frame and Earth rotation parameters to natural hazard monitoring. The Space Geodesy Group has operated the first International GNSS Service (IGS) Global Data Center (GDC) in Asia and Oceania since 2006. The KASI GDC archives data directly from Asia and Oceania and hosts new regional IGS stations in this area; it also distributes all IGS data and products. It also operates the KASI GNSS Network, including nine GNSS stations over Korea to provide high-quality data in support of civilian and scientific applications. It is committed to supporting many challenging research areas using GNSS data. Another mission of the Space Geodesy Group is to publish the Korean Astronomical Almanac, which is an annual publication including information such as a calendar, the rising and setting times of the Sun and Moon, the time of twilight, and information about eclipses.