MEASUREMENT OF POLARIZATION CHARACTERISTICS OF VHF RADIO-WAVES REFLECTED BY THE E(S) LAYER

To investigate the change of the rotation of the polarization plane of the very-high frequency (VHF) radiowave after reflection by the spora dic E layer, a television wave transmitted from Seoul, Korea, was meas ured in Tokyo. In this paper, the measurement principle and equipment for the rotation of the polarization plane are described. From the mea sured results, it is shown that most of the measured values have rotat ion by a certain angle from the polarization state of the transmission and exhibit fine changes swiftly and randomly within 40 to 90 degrees centered at the rotated angle. Sometimes, there is a case of slow rot ation from +90 degrees to -90 degrees. Further, the cause of the rotat ing characteristics of the polarization plane is presented from the Fa raday rotation theory.