Abstract
The FormoSat-3/ Constellation Observing System for Meteorology, Ionosphere and Climate (FS3/COSMIC) has been proven a successful mission on profiling ionospheric electron density \(( {N_e })\) using the radio occultation (RO) technique. A follow-on program (called FS7/COSMIC2) is now in progress. The FS3/COSMIC follow-on mission will have six 24\(^{\circ }\)-inclination and 550-km low Earth orbiting (LEO) satellites and six 72\(^{\circ }\)-inclination and 750-km LEO satellites to receive Tri-G (GPS, GLONASS, and Galileo) satellite signals. FS7/COSMIC2 RO observations were simulated in this study by calculating limb-viewing GNSS-to-LEO TEC values separately through two independent ionospheric models (the TWIM and NeQuick models). We propose a compensatory Abel-inversion scheme to improve vertical \(N_e \) profiling and three-dimensional (3D) \(N_e \) modeling in this FS7/COSMIC2 simulation study with future real observations. In this FS7/COSMIC2 feasibility study the number of RO observations will increase of around 10 times compared with FS3/COSMIC, and the windowing day number to collect \(N_e \) profiles and to derive every half-hour 3D \(N_e \) model could be decreased from 30 to 3 days. The results show that the root-mean-square (RMS) foF2 and hmF2 difference improvements are 46 % (32 %) and 21 % (4.6 %), respectively, in relative percentage over the standard Abel inversion at the TWIM-background (NeQuick-background) simulation experiment. The RMS modeling errors are about one order less than those from FS3/COSMIC simulations.
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Acknowledgments
This work has been supported by Ministry of Science and Technology, Taiwan, R.O.C. through Project Nos. MOST 103-2111-M-008-022 and NSC 102-2923-M008-002-MY3. The authors express their appreciation to Ionosphere Radio Propagation Unit of the T/ICT4D Laboratory for providing the NeQuick model source code. The authors would also like to thank UCAR’s CDAAC and NSPO Satellite Operations Control Center (SOCC) for providing FS3/COSMIC satellites data.
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Tsai, LC., Su, SY., Liu, C.H. et al. Ionospheric electron density profiling and modeling of COSMIC follow-on simulations. J Geod 90, 129–142 (2016). https://doi.org/10.1007/s00190-015-0861-x
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DOI: https://doi.org/10.1007/s00190-015-0861-x