Astronomy:S4 Index

From HandWiki
Short description: Parameter used to measure ionospheric disturbances

The [math]\displaystyle{ S_4 }[/math] Index is a standard index used to measure ionospheric disturbances. It is defined as the ratio of the standard deviation of signal intensity to the average signal intensity.[1]

Real Time data

This parameter is displayed in real time by many institutions:

References

  1. Basu, Santimay; Basu, Sunanda. Scintillation technique for probing Ionospheric irregularities. p. 128.