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RADIO ASTRONOMY INDEX - New

SID: Sudden Ionospheric Disturbance
April 25, 2014, 0017 UT

  • Sudden Ionospheric Disturbance (SID)
    • Below is the Tektronix MDO4104-6 spectrum analyzer display showing the SID from 17.5 MHz to 24.0 MHz at 0038 UT.
    • The X-ray flare ionized the lower layers of the earth's ionosphere causing an increase in absorption of terrestrial radio signals.
    • Notice the change in signals in the top half of the spectrogram and the radio blackout in the bottom half of the spectrogram.
    • The radio blackout shown in the spectrogram is greater than 15 minutes long.

     
  • Spectrogram
    • The spectrum analyzer spectrogram is the blue display (the top window)
      • The spectrogram horizontal axes is from 17.5 MHz to 24 MHz.
      • The top blue display vertical axis is time with the oldest time is at the top.
      • The black bottom display is the latest spectrum trace at 00:38:54 UT.
    • The vertical white lines are radio signals that are being received.
      • The faint very thin vertical lines are local radio frequency interference (RFI) which is not affected by the change in the ionosphere.
      • The white vertical dots are short duration radio signals.
    • Many of the vertical white lines stopped at the time of the X-ray flare in the middle of the spectrogram.
      • Also, there is a decrease of overall background radio noise (white blueish color) during the blackout.

     
  • Radio Bands
    • The first set of strong signals from the left edge is the 17.5 MHz to 17.9 MHz broadcasting band.
    • The second set of strong signals from the left edge is the 17 meter (18.068 MHz to 18.168 MHz) amateur radio band.
    • Radio station WWV at 20.0 MHz is the blue vertical line in the spectrogram just over one division left of center.
      • WWV is 1,511 km with a bearing of 105.3 degrees.
    • The strong set of signals just right of the center frequency is the 15 meter (21.0 MHz to 21.45 MHz) amateur radio band.

SID: Sudden Ionospheric Disturbance


  • Below is the Tektronix MDO4104-6 spectrum analyzer display showing the SID from approximately 20.1 MHz to 24.0 MHz at 0050 UT.
  • Radio station WWV at 20.0 MHz is the blue vertical line in the spectrogram just over one division left of center.

SID: Sudden Ionospheric Disturbance


United States Frequency Allocations

United States Frequency Allocations



Summary

Tektronix MDO4104-6 spectrum analyzer.

  • 17.5 MHz start frequency
  • 20.75 MHz center frequency
  • 24.0 MHz stop frequency
  • 6.5 MHz frequency span
  • 6.5 MHz capture bandwidth
  • 100 Hz resolution bandwidth
  • 650 kHz per horizontal division
  • 5 dBm per vertical division
  • ~7 seconds spectrum update rate
  • Spectrogram bottom is the current spectrum trace shown at the bottom of the display.
  • Spectrogram top is the oldest spectrum, approximately 30 minutes after the current spectrum trace at the bottom.


Observing Information

  • OBS-Location: Camas, WA USA, 16.6 miles East-North-East from the center of Portland, OR, USA


Tektronix  MDO4104-6

Spectrum Analyzer Equipment


Software


Radio JOVE Data Archive Calendar


Verifying SID Caused by X-Flare

NOAA/ National Weather Service
National Centers for Environmental Prediction
Space Weather Prediction Center
Solar Event Reports (Edited Events)

  • Solar X-flare began at 0017 UT and ended at 00383 UT
  • Reporting observatory G15: GOES spacecraft for the observatory
  • Event XRA: X-ray event from SWPC's Primary or Secondary GOES spacecraft
  • Particulars: Intensity X1.3

Product: 20140425events.txt
:Created: 2014 Apr 26 2102 UT
:Date: 2014 04 25
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
# Please send comments and suggestions to SWPC.Webmaster@noaa.gov 
#
# Missing data: ////
# Updated every 30 minutes.
#                            Edited Events for 2014 Apr 25
#
#Event    Begin    Max       End  Obs  Q  Type  Loc/Frq   Particulars       Reg#
#-------------------------------------------------------------------------------

4870       0017   0027      0038  G15  5   XRA  1-8A      X1.3    1.1E-01   2035


NASA STEREO / WAVES

  • NASA WIND-WAVES: The Radio and Plasma Wave Investigation on the WIND Spacecraft
  • NASA STEREO (Solar TErrestrial RElations Observatory)
  • NASA STEREO / WAVES data

    WIND STEREO


    Links