GNSS radio occultation (RO) leverages GNSS satellites rising and setting on the horizon to extract refractivity in the troposphere and the ionosphere. Traditionally, highly specialized scientific instruments have been deployed on low-Earth-orbiting (LEO) platforms to collect GNSS-RO soundings where the first LEO GPS-RO experiment was performed in 1995 by the Microlab 1 satellite (Ware et al., 1996). Subsequently, there have been numerous successful missions that utilize GNSS signals for atmospheric and ionospheric soundings (Yue et al., 2011). The joint U.S.-Taiwan Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) was launched in 2006 and represents the first dedicated LEO constellation of six satellites employing GNSS-RO techniques (Anthes et al., 2008;Kumar, 2006). The success of COSMIC demonstrated the operational value of these soundings in weather prediction, space weather monitoring, and geodesy.