风云气象卫星与商业卫星的掩星分布与协同观测OA

GNSS Radio Occultation(RO)serves as a key technique for constructing a global high-pre-cision atmospheric and ionospheric sounding capability.China's operational Fengyun-3(FY-3)RO sys-tem produces data of exceptional quality,characterized by high accuracy,stability,and standardization,making it the current accuracy benchmark in RO sounding.However,due to its orbital configuration,the FY-3 system alone still exhibits coverage gaps in equatorial and polar regions.In recent years,the rapid development of commercial constellations such as Tianmu and Yunyao has enabled multi-source RO cooperative observations,offering a promising approach to enhance the spatiotemporal density of RO data.Based on RO measurements from the FY-3,Tianmu,and Yunyao constellations,this study sys-tematically evaluates the spatial distribution characteristics and joint observation benefits of the three systems.Results demonstrate that integrating commercial constellations significantly increases the num-ber of global RO events and improves coverage at low and high latitudes.Local time coverage is also en-hanced from segmented intervals to nearly continuous throughout the day.Despite the considerable im-provement in observational density,data overconcentration in certain mid-latitude areas and small-scale gaps under high-resolution analysis remain,indicating that orbital configurations and constellation coor-dination require further optimization.This study provides quantitative references for the future collabo-rative development of China's FY-3 and commercial RO constellations.