基于几何光学反演方法,由附加相位延迟序列出发,对2007年6月6日发生在澳大利亚上空的一次COSMIC掩星事件进行了反演。将反演得到的折射角、折射率、干温与湿度廓线分别与COSMIC数据分析与管理中心(COSMIC data analysis and archive center,CDAAC)的相应产品进行了比较。结果表明,两者在低对流层存在较显著的差异。以距离该掩星地点300km以内、观测时间差异2h以内的无线电探空资料为参照,反演的折射率廓线与CDAAC的折射率廓线在低对流层都存在一定的误差。对于该掩星事件,CDAAC通过变分法反演的湿度廓线并不比本文的反演结果更接近探空廓线;在1km以下,其变化趋势甚至与探空结果相矛盾。
Based on geometric optics method, the atmospheric profiles are inverted from the excess phase delays of a COSMIC RO event (ROE) occurring on June 6, 2007 over Australia. The inverted profiles, including bending angle profile, refractivity profile, dry tempera- ture profile and humidity profile, are compared with corresponding data products provided by COSMIC data analysis and archive center (CDAAC). The results show that the application of radio holographic method to the inversion process of CDAAC leads to the differences between the profiles inverted by this paper and by CDAAC in the lower troposphere (LT). With a radiosonde sounding occuring within 2 hours and 300 km of the ROE as reference, er- rors are found in the refractivity profiles inverted by this paper and by CDAAC in LT. For the chosen ROE, the errors in the humidity profile provided by CDAAC, which is inverted with variational method, are even larger than the humidity profile inverted by us with direct method.