UABSE Codes

Ionospheric absorption measurement by riometer technique or by ionospheric forward scatter or by VLF recordings.

Example:

Definition of symbols:

  • UABSE comes from ionospheric ABSorption, codeE

  • I I I I I = station indicator

  • DD = UT day of observation
  • T = type of measurement
    • 1 = riometer
    • 2 = forward scatter
    • 3 = VLF phase advance (rarely retardation which requires use of group dddHH instead of group ccXHH
  • HH = UT hour of message

  • a = type of phenomenon
    • 1 = SCNA (sudden cosmic noise absorption) (if it is associated with a solar flare, it is normally reported by code USIDO)
    • 2 = SPA (sudden phase anomaly) (if it is associated with a solar flare, it may be reported by code USIDO)
    • 3 = Aurora-associated absorption
    • 4 = PCA (polar cap absorption event) due to protons
    • 5 = PCA (polar cap absorption event) due to relativistic electrons
    • 6 = noise storm of solar radio emission superposed on absorption
    • 7 = slowly varying ionospheric absorption-defines onset time of magnetospheric sub-storm at auroral zone stations near the midnight meridian (Eather and Jacka, Australia J. Physics 19, 215, 1966).
  • HHmm = UT hour and minute of beginning of phenomenon

  • 9 = indicates time of maximum follows
  • HHmm = UT hour and minute of maximum of event

Note: Omit group bHHmm if maximum time is not known

  • If T = 1 or 2 in DDTHH use the following group:

  • cc = number of decibels of maximum absorption before hour indicated by next HH
  • / = filler
  • HH = UT hour of end time of event (if the event is still in progress at the time of the message, use / /)
  • If T = 3 in DDTHH use the following group:

  • d d d = phase advance (rarely retardation) in degrees
  • HH = UT hour of end time of event (if the event is still in progress at the time of the message, use / /)

Note: / is to be used for data not available.