The FORMOSAT-7/COSMIC-2 (F7C2) satellite mission is designed to support radio occultation (RO) studies, with orbit solution derived from reduced-dynamic orbit determination. This work assesses the status performance of F7C2 satellites, focusing on the variation of solar panel trim angle, data availability, phase residuals from precise orbit determination (POD), and orbit validation. The panel trim angle varies with the \(\:\beta\:\) angle, which is the sun elevation with respect to the orbital plane. The variation of the panel trim angle leads to the Y-bias, which affects the drag-induced acceleration. On the other hand, the F7C2 satellite equips with two POD antennas in receiving the GNSS signals. We assess the posteriori sigma of L1 phase from the POD with both single- and dual-antenna configurations, where the GPS-only and GPS + GLONASS tracking data is used. Overall, POD solution from the dual-antenna configuration with GPS + GLONASS data is more preferrable than that with GPS-only data due to consistent orbit solutions over three years. The orbit fitting technique is used to validate orbit solutions from the National Cheng Kung University (NCKU) and the University Corporation for Atmospheric Research (UCAR). The RMS of orbit residual from the orbit fitting in both the NCKU and the UCAR solutions are to approximate to 0.13 m, 1.2 m, and 0.02 m in radial, along-track, and cross-track directions in high \(\:\beta\:\) cases, and approximately 0.13 m, 0.40 m, and 0.03 m in low \(\:\beta\:\) cases. Large orbit residuals in the along-track direction are mainly caused by the Y-bias, which is not modeled in the orbit fitting. With the Y-bias correction model, the orbit accuracy is close to 0.13, 0.19 and 0.03 m in the radial, along-track and cross-track directions in the high β and 0.11, 0.17 and 0.02 m in the low β. Furthermore, the RMS of orbit differences between NCKU and UCAR solutions is 10.3 cm, 14.2 cm, 3.3 cm in the radial, along-track, cross-track directions in high \(\:\beta\:\) and 9.2 cm, 12.3 cm, 2.7 cm in low \(\:\beta\:\) . This work assesses the performance of the F7C2 orbit and identifies the related issues linked to the Y-bias effect.
