Real-Time Ionospheric Scintillation Monitoring

As the millennium approaches we are faced with a period of increasing solar flux and intense ionospheric scintillation. Not only single-frequency, but also dualfrequency GPS measurements will be badly affected by deep scintillation, due to its temporal and spatial decorrelation characteristics. Using the scintillation observables derived from dual-frequency phase and signal-to-noise ratio measurements, real-time scintillation detection, tracking and indication algorithms have been developed. By an orthonormal projection of the scintillation observables to the timefrequency spaces of different scales, and using multiscale statistical hypothesis tesing, a fast and reliable scintillation detection and tracking can be achieved. A fuzzy expression for “scintillation depth” is also developed to overcome the ambiguity existing in the numerical and linguistic definitions of scintillation intensity.