COSMIC与FY-3C掩星电离层反演的比较

Comparison of ionospheric inversions between COSMIC and FY-3C radio occultation missions

利用基于TEC的电子密度廓线反演方法,对2014年12月31日的COSMIC和FY-3C掩星任务的电离层掩星相位数据进行处理,将反演的电子密度廓线及电离层峰值参数分别与两个掩星任务的官方产品进行比较,发现两个掩星任务的反演结果与官方产品均具有较好的一致性.其中COSMIC反演结果与CDAAC官方产品的一致性略好于FY-3C反演结果与NSMC官方产品的一致性,且两个任务的NmF2的反演质量均优于hmF2的反演质量.但与COSMIC不同,FY-3C掩星电离层相位数据进行反演处理之前有必要进行滤波平滑预处理,且由于FY-3C非掩星时段的相位数据量太少,反演过程中不建议对TEC进行改正.

With the Total Electron Content(TEC)-based Electron Density Profile(EDP)inversion method,the phase data of Radio Occultation(RO)events of Constellation Observing System for Meteorology,Ionosphere and Climate(COSMIC)and Fengyun-3C(FY-3C)missions are processed.The inverted EDPs and ionospheric peak parameters are compared with the official products of the two RO missions,respectively.It is found that although good consistencies exist between the inverted results and the official products for both of the two missions,the con-sistency is more significant for COSMIC mission.Besides,for both of the two RO missions,the consistence between the inverted NmF2 values and the official products is better than that between the inverted hmF2 values and the offi-cial products.There are some differences in detailed inversion processes between the two RO missions.First,it is necessary to smooth the phase data before the EDP inversion process for FY-3C mission,which is not the case for COSMIC mission.Second,although TEC correction is effective for COSMIC RO EDP inversions,it is not a recom-mended practice in FY-3C EDP inversion process due to the non-availiability of enough non-RO period phase data in FY-3C RO mission.