11:00 AM - 1:00 PM
[PEM12-P04] Improved real-time three-dimensional ionospheric tomography based on GNSS and ionosonde observations
Keywords:GNSS ionospheric tomography, Real-time ionospheric monitoring, Ionosonde assimilation to GNSS tomography
The real-time ionosonde data from four ionosonde stations in Japan (Wakkanai, Kokubunji, Yamagawa, and Okinawa) are used to assimilating into the GNSS tomography. Auto-scaled ionosonde parameters, hpF2 and foF2 are obtained as soon as the ionosonde observation and analysis finishes to estimate ionospheric peak density (NmF2) and height (hmF2). NmF2 and hmF2 are assimilated with the results of the original tomography results.
Preliminary comparison with the ionospheric density profile obtained by incoherent scatter observations by the MU radar showed that the improved real-time tomography provided the ionospheric density profile closer to the MU radar results than the current real-time tomography without ionosonde assimilation.
Mainly due to improved hardware which is still a normal desktop workstation and mathematical library, the process time has been reduced to about 2 minutes, which could realize real-time tomography analysis every 5 minutes.
While the preliminary results are promising, tuning of parameters involved in the tomography process is necessary to further improve the results. The parameters to be examined include the constraint about smoothness between adjacent voxels, ambiguity of ionosonde and TEC, correlation length in the assimilation, and weight factor between the original tomography and assimilation.