Interferometric synthetic aperture radar (InSAR) is now routinely used to generate topographic data and to study geophysical phenomena, such as crustal deformation, ice motion and structure, and vegetation canopy depths [1]. In this study, we show that ionospheric disturbances can distort InSAR phase and correlation maps, and, further, that accurate image coregistration can compensate for ionos...

Ionospheric scintillation occurs mainly at high and low latitude regions of the Earth and may impose serious degradation on GNSS (Global Navigation Satellite System) functionality. The Brazilian territory sits on one of the most affected areas of the globe, where the ionosphere behaves very unpredictably, with strong scintillation frequently occurring in the local postsunset hours. The correlat...

This work studies the sudden increases in total electron content of the ionosphere caused by the very intense solar flare on July 14, 2000. Total electron content (TEC) data observed from a Global Positioning System (GPS) network are used to calculate the flare-induced TEC increment, dTECf, and variation rate, dTECf/dt. It is found that both dTECf/dt and dTECf are closely related with the solar...

Extremely large ionospheric spatial gradients could cause potential integrity threats to Ground-Based Augmentation System (GBAS) users. The importance of understanding ionosphere behavior is not limited to cases of extreme ionospheric events. Broader knowledge of both nominal and anomalous ionospheric behavior would help improve the design and operation of GBAS. We developed an automated tool f...

This is anOp Abstract – This work reviews an ionospheric activity indicator useful for identifying disturbed periods affecting the performance ofGlobal Navigation Satellite System (GNSS). This index is based in the AlongArc TEC Rate (AATR) and can be easily computed from dual-frequency GNSS measurements. The AATR indicator has been assessed over more than one Solar Cycle (2002–2017) involving a...

The natural phenomenon that most significantly affects GNSS positioning accuracy is the ionosphere. The GNSS satellite signals interact with free electrons along the propagation path to the receiver, leading to a group delay and phase advance proportional to the Total Electron Content (TEC). These refractive effects cause errors in the satellite range measurements which, if uncorrected, degrade...

The design of GNSS2 presents the international navigation community a unique opportunity to design a signal for more precise positioning than is currently available with GPS and GLONASS. Faster and longer acquisition codes would improve code positioning accuracy and signal cross-correlation, as well as providing a greater number of unique codes for pseudolites. Furthermore, receivers may be abl...

In this paper, a novel method for rain rate estimation is researched by polarimetric phase shift of the Global Navigation Satellite System (GNSS). The physical process of GNSS signals propagating through rain-filled medium is investigated, by which the cause of polarimetric phase shift is explored. Then, a theoretical model between polarimetric phase shift ∆φ and rain rate R is established and ...

forenoon but failed on June 19. Weak transmission by scattered reflections also failed. Absorption of Ftransmission from WSXAL (6060 kc/s, 650 km distant) was greater than normal on June 19. The F2 virtual heights were very high when fz,* began to increase above fp, * from 1400 to 1600 EST June 19. This example of correlation of the condition of the ionosphere with a magnetic storm corroborates...

[1] The Equatorial Ionization Anomaly (EIA) is a significant feature of the low-latitude ionosphere. During daytime, the eastward electric field drives a vertical plasma fountain at the magnetic equator creating the EIA. Since the eastward electric field is also the driving force for the Equatorial Electrojet (EEJ), the latter is positively correlated with the EIA strength. We investigate the c...