Radio Science

Faraday Rotation of the 136 MHz Transmission From the Geostationary Satellite ‘Canary Bird’ Observed at Nairobi


  • A. N. Hunter


The 136 MHz transmissions from 'Canary Bird' were recorded at Nairobi, 1.32°S, 36.8°E, 26°(dip) from June 1967 through February 1968. The receiving system used a Yagi aerial rotating 1 rev in 6 sec. Plots of diurnal variation of Faraday rotation are given for the months of July, October, November, and December 1967 and January and February 1968. These plots show general agreement with the mean diurnal variation of total electron content as determined from the traveling satellite BE-B. One important feature which is much more marked in the geostationary satellite records is a large increase in total electron content at about 2300 hours; at this time there is commonly a marked lowering of ionosphere height. This peak, which is also apparent in foF2, is thought to be associated with movement of the equatorial anomaly maxima.