Abstract:
The FormoSat-3/ Constellation Observing System
for Meteorology, Ionosphere and Climate (FS3/
COSMIC) has been proven a successful mission on pro-
filing ionospheric electron density (Ne) 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◦-inclination and 550-km
low Earth orbiting (LEO) satellites and six 72◦-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 limbviewing
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 Ne profiling and three-dimensional (3D)
Ne 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 Ne profiles and to derive every
half-hour 3D Ne 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 (NeQuickbackground) simulation experiment. The RMS modeling
errors are about one order less than those from FS3/COSMIC
simulations.
