First Evidences of Ionospheric Plasma Depletions Observations Using GNSS-R Data from CYGNSS

At some frequencies, Earth’s ionosphere may significantly impact satellite communications, Global Navigation Satellite Systems (GNSS) positioning, and Earth Observation measurements. Due to the temporal and spatial variations in the Total Electron Content (TEC) and the ionosphere dynamics (i.e., fluctuations in the electron content density), electromagnetic waves suffer from signal delay, polarization change (i.e., Faraday rotation), direction of arrival, and fluctuations in signal intensity and phase (i.e., scintillation). Although there are previous studies proposing GNSS Reflectometry (GNSS-R) to study the ionospheric scintillation using, for example TechDemoSat-1, the amount of data is limited. In this study, data from NASA CYGNSS constellation have been used to explore a new source of data for ionospheric activity, and in particular, for travelling equatorial plasma depletions (EPBs). Using data from GNSS ground stations, previous studies detected and characterized their presence at equatorial latitudes. This work presents, for the first time to authors’ knowledge, the evidence of ionospheric bubbles detection in ocean regions using GNSS-R data, where there are no ground stations available. The results of the study show that bubbles can be detected and, in addition to measure their dimensions and duration, the increased intensity scintillation (S4) occurring in the bubbles can be estimated. The bubbles detected here reached S4 values of around 0.3–0.4 lasting for some seconds to few minutes. Furthermore, a comparison with data from ESA Swarm mission is presented, showing certain correlation in regions where there is S4 peaks detected by CYGNSS and fluctuations in the plasma density as measured by Swarm.

[1]  Adriano Camps,et al.  Improved characterization and modeling of equatorial plasma depletions , 2018 .

[2]  G. Zängl,et al.  ICON‐A, the Atmosphere Component of the ICON Earth System Model: I. Model Description , 2018, Journal of Advances in Modeling Earth Systems.

[3]  Adriano Camps,et al.  Improved modelling of ionospheric disturbances for remote sensing and navigation , 2017, 2017 IEEE International Geoscience and Remote Sensing Symposium (IGARSS).

[4]  Randall Rose,et al.  The nasa cygnss mission: Overview and status update , 2017, 2017 IEEE International Geoscience and Remote Sensing Symposium (IGARSS).

[5]  Peter Korn,et al.  Formulation of an unstructured grid model for global ocean dynamics , 2017, J. Comput. Phys..

[6]  Mamoru Yamamoto,et al.  Vertical rise velocity of equatorial plasma bubbles estimated from Equatorial Atmosphere Radar (EAR) observations and HIRB model simulations , 2017 .

[7]  Hyuk Park,et al.  Ionospheric Effects in GNSS-Reflectometry From Space , 2016, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing.

[8]  Adriano Camps,et al.  Tutorial on Remote Sensing Using GNSS Bistatic Radar of Opportunity , 2014, IEEE Geoscience and Remote Sensing Magazine.

[9]  Z. Jelenak,et al.  The NASA EV-2 Cyclone Global Navigation Satellite System (CYGNSS) mission , 2012, 2013 IEEE Aerospace Conference.

[10]  Massimo Materassi,et al.  Scintillation modeling using in situ data , 2007 .

[11]  Edgar H. Satorius,et al.  Channel modeling and simulation for mobile user objective system (MUOS)--part 1: flat scintillation and fading , 2003, IEEE International Conference on Communications, 2003. ICC '03..

[12]  Y. Béniguel,et al.  Global Ionospheric Propagation Model (GIM): A propagation model for scintillations of transmitted signals , 2002 .

[13]  IONOSPHERIC PROPAGATION DATA AND PREDICTION METHODS REQUIRED FOR THE DESIGN OF SATELLITE SERVICES AND SYSTEMS , 1999 .

[14]  Stephen J. Katzberg,et al.  Detection of ocean reflected GPS signals: theory and experiment , 1997, Proceedings IEEE SOUTHEASTCON '97. 'Engineering the New Century'.

[15]  J. Stephen,et al.  Utilizing GPS To Determine Ionospheric Delay Over the Ocean , 1996 .

[16]  J. A. Secan,et al.  Modeling and scientific application of scintillation results , 1984 .

[17]  D. Knepp.  Multiple phase-screen calculation of the temporal behavior of stochastic waves , 1983, Proceedings of the IEEE.

[18]  R. Crane,et al.  Ionospheric scintillation , 1977, Proceedings of the IEEE.