Data Access
Ionospheric scintillation is a rapid fluctuation of radio-frequency signal phase and/or amplitude, generated as a signal passes through the ionosphere. Scintillation occurs when a radio frequency signal in the form of a plane wave traverses a region of small scale irregularities in electron density. The irregularities cause small-scale fluctuations in refractive index and subsequent differential diffraction (scattering) of the plane wave producing phase variations along the phase front of the signal. As the signal propagation continues after passing through the region of irregularities, phase and amplitude scintillation develops through interference of multiple scattered signals. The Ionospheric Scintillation Monitor in Willis Island was installed in 11/12/2010 and still works now.
Version:2.3.2
Ionospheric scintillation is a rapid fluctuation of radio-frequency signal phase and/or amplitude, generated as a signal passes through the ionosphere. Scintillation occurs when a radio frequency signal in the form of a plane wave traverses a region of small scale irregularities in electron density. The irregularities cause small-scale fluctuations in refractive index and subsequent differential diffraction (scattering) of the plane wave producing phase variations along the phase front of the signal. As the signal propagation continues after passing through the region of irregularities, phase and amplitude scintillation develops through interference of multiple scattered signals. The Ionospheric Scintillation Monitor in Willis Island was installed in 11/12/2010 and still works now.
| Role | Person | StartDate | StopDate | Note | |
|---|---|---|---|---|---|
| 1. | GeneralContact | spase://ASWS/Person/Kehe.Wang | |||
| 2. | MetadataContact | spase://ASWS/Person/Kehe.Wang |
includes descriptions of station logfiles, data formats and examples and hardware
includes browse display interface, button to get daily data file and link to data availability chart
Online viewer of real time Ionospheric Scintillation Monitor data, Latest Conditions, Regional Map, Recent Scintillation Events.
Access to the station Ionospheric Scintillation Monitor data data of Willis Island.
S4 is a dimensionless number with a theoretical upper limit of 1.0, commonly estimated over an interval of 60 seconds.
There are two defined regimes of amplitude scintillation: weak and strong, which roughly correspond to the type of scattering associated with each. Strong scintillation is generally considered to occur when S4 is greater than ~0.6 and is associated with strong scattering of the signal in the ionosphere. Below this is weak scintillation. An S4 level below 0.3 is unlikely to have a significant impact on GPS.
Phase scintillation is quantified by the Prms (or Φrms) index which is defined as the standard deviation of the signal phase over a given time interval. This index is measured either in radians or degrees. A Prms greater than ~ 1° is considered to be strong scintillation. At mid-latitudes, Prms rarely exceeds 1° for more than 1% of the time.