Amateur Radio Propagation Studies     Research Section                             www.qsl.net/ik3xtv                   


   Research team on this project: ik3xtv and ik1uwl                                                                                     last update  July, 20-2013

                                                                                

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   Research in progress: Interaction with the Ionosphere, effects in EME  


 

 

Copyright  2013 © Amateur Radio Propagation Studies. All rights reserved.

Interaction with the Ionosphere, effects in EME
This project of research is focusing on the Faraday effect and Ionospheric interaction in EME Amateur Radio communication. Our aim is relating the Faraday effect with Space wheater conditions, geomagnetic indices and geographical location.                                                                                                                                        

 


Abstract: Faraday rotation in the ionosphere      (Courtesy : ITU Recommendation ITU-R  P.531-11- 02-2012)

When propagating through the ionosphere, a linearly polarized wave will suffer a gradual rotation of its plane of polarization due to the presence of the geomagnetic field and the anisotropy of the plasma medium. The magnitude of Faraday rotation, q, will depend on the frequency of the radiowave, the magnetic field strength, and the electron density of the plasma as:

Ф=2,36 * 10^-14 * Bav NT/f²

where:

                                  Ф:      angle of rotation (rad)

                               Bav :      average Earth magnetic field (Wb × m–2 or Teslas)

                                   f :      frequency (GHz)

                                NT :      TEC (electrons × m–2).

                                             

 

Typical values of q are shown in Fig. 1.

The Faraday rotation is thus inversely proportional to the square of frequency and directly proportional to the integrated product of the electron density and the component of the Earth's magnetic field along the propagation path. Its median value at a given frequency exhibits a very regular diurnal, seasonal, and solar cyclical behaviour that can be predicted. This regular component of the Faraday rotation can therefore be compensated for by a manual adjustment of the polarization tilt angle at the earth-station antennas. However, large deviations from this regular behaviour can occur for small percentages of the time as a result of geomagnetic storms and, to a lesser extent, large-scale travelling ionospheric disturbances. These deviations cannot be predicted in advance. Intense and fast fluctuations of the Faraday rotation angles of VHF signals have been associated with strong and fast amplitude scintillations respectively, at locations situated near the crests of the equatorial anomaly.

 

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Contact: ik3xtv@gmail.com      Copyright  2013 © Amateur Radio Propagation Studies. All rights reserved.


WEBSITE POLICY : The scientific researches issued in this site are exclusively related to Amateur Radio experiments and studies and are not for profit or commercial use