Ionospheric Sounding Using GNSS-RO - GNSS Remote Sensing: Theory, Methods and Applications - page 171

related to the earthquake, tsunami, rocket lunching and some other events (Calais
and Minster 1995 ; Afraimovich and Kiryushkin 2002 ; Liu et al. 2006 , 2011 ;Wan
et al. 2005 ; Ding et al. 2008 ). The GNSS-RO provides 3-D ionospheric profile
information, which better monitor ionospheric anomalies. Although there are dense
continuous GNSS operational networks, such as in USA, Japan and Europe, but
ground GNSS stations are still not enough to monitor global ionospheric variations,
e.g., in the oceans and polar region, while GNSS-RO can provide long-term and
global coverage observations. Therefore, GNSS-RO has wide advantages to monitor
ionospheric anomalies, such as traveling ionospheric disturbances related to AGW
(acoustic gravity wave), equatorial anomalies and so on.

7.5.4 Ionospheric Scintillation

Ionospheric scintillation is caused by small scale irregularities in the ionosphere,
which will result in a rapid fluctuation of the radio signals when they go through
the irregularities areas. The phase front of the signal will change because of the
small-scale fluctuations in refractive index and subsequent scattering. Scintillation
index can be derived using GNSS-RO amplitude observation (Pavelyev et al. 2007 ).
Using GNSS-RO data to construct an ionospheric scintillation model, it will have
wide applications.

References

Afraimovich EL, Kiryushkin VV (2002) Space-multichannel reception for ionosphere monitoring
during launches. Quantum Electron Radio Phys 11:46-53
Austen JR, Franke SG, Liu CH (1988) Ionospheric imaging using computerized tomography.
Radio Sci 23:299-307
Calais E, Minster JB (1995) GPS detection of ionospheric perturbations following the January 17,
1994, Northridge Earthquake. Geophys Res Lett 22(9):1045-1048
Datta-Barua S, Walter T, Blanch J, Enge P (2008) Bounding higher-order ionosphere errors for the
dual-frequency GPS user. Radio Sci 43:RS5010. doi : 10.1029/2007RS003772
Ding F, Wan W, Liu L et al (2008) A statistical study of large scale traveling ionospheric
disturbances observed by GPS TEC during major magnetic storms over the years 2003-2005.
J Geophys Res 113:A00A01. doi: 10.1029/2008JA013037
Fjeldbo GF, Eshleman VR, Kliore AJ (1971) The neutral atmosphere of Venus as studied with the
Mariner V radio occultation experiments. Astron J 76:123-140
Gorbunov ME, Gurvich AS, Kornblueh L (2000) Comparative analysis of radioholographic
methods of processing radio occultation data. Radio Sci 35(4):1025-1034
Hajj GA, Romans LJ (1998) Ionospheric electron density profiles obtained with the Global
Positioning System: results from the GPS/MET experiment. Radio Sci 33(1):175-190
Hocke K (1997) Inversion of GPS meteorology data. Ann Geophys-Atmos Hydrospheres Space
Sci 15(4):443-450
Hofmann-Wellenhof B, Lichtenegger H, Collins J (1992) GPS theory and practice. Springer,
Wien/New York