Tuesday, 16 January 2007: 8:30 AM
Detecting equatorial plasma bubbles with GPS phase scintillation
210A (Henry B. Gonzalez Convention Center)
The increased reliance on trans-ionospheric communication signals has necessitated the investigation of remote sensing techniques to provide data to existing ionospheric assimilation and physics based models. The lower latitude regions of the ionosphere have proved to be particularly challenging in the post-sunset time period. In this domain, space weather events such as equatorial plasma bubbles (EPB) can cause large density gradients that degrade or completely disrupt signals from satellites. The detection and characterization of these disturbances can assist in defining an ionospheric specification for use in signal impact definition. Measurements of the electron density variations as well as the phase and amplitude scintillations at VHF, UHF and GPS frequencies have been used in the detection of these ionospheric disturbances. This paper will explore the use of near real-time GPS phase scintillation measurements to detect plasma bubbles. The phase scintillation strength is calculated in near real-time, utilizing high rate observations from a global GPS receiver network. The subsequent usage of this parameter as an indicator of EPB evolution is investigated, showing correlation between the phase scintillation and known time periods of ionospheric disturbances. We present case studies used in our evaluation of the physics based models forecasting capabilities when driven with instabilities identified using the phase scintillation.