掩星数据在数值预报和气候监测中具有重要价值。本研究利用FY-3E/GNOS和COSMIC-2卫星的掩星数据，结合欧洲中期天气预报第五代再分析资料（ERA5），系统分析了两种掩星数据产品在不同高度和纬度下的偏差特征。结果表明，在 5~30 km的高度范围内，FY-3E/GNOS和 COSMIC-2的折射率与ERA5数据的一致性较好，偏差小于1%，弯角偏差稳定在±0. 4%以内；但在低层大气（5 km以下），COS‐MIC-2弯角在 4 km 以下出现最大为-1. 2% 的负偏差，FY-3E/GNOS弯角则在 5 km 以下表现出系统性的正偏差，折射率在低纬度区域2 km以下呈负偏差，2~4 km为正偏差。研究发现，FY-3E/GNOS的弯角廊线比COSMIC-2更为平滑，特别是在对流层下层。

Radio Occultation data are of great value in numerical weather forecasting and climate monitoring. This study evaluates the deviation characteristics of occultation data from the FY-3E/GNOS and COSMIC-2 satellites with ERA5 reanalysis data. The results indicate that FY-3E/GNOS and COSMIC-2 exhibit high consistency with ERA5 in the altitude range of 5 km to 30 km，with refractivity deviations less than 1% and bending angle deviation is stable within ±0. 4%. However，in the lower atmosphere（below 5 km），COSMIC-2 presents a maximum negative bias of -1. 2% at altitudes below 4 km，while FY-3E/GNOS demonstrates a systematic positive bi‐ as below 5 km in the bending angle，and the refractivity shows negative deviations below 2 km in the low-latitude region and positive deviations from 2 to 4 km. Research findings indicate that the bending angle profiles of FY-3E/GNOS are smoother than those of COSMIC-2，especially in the lower troposphere.