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The report details original equipment for continuously recording Pc1 geomagnetic micropulsations on magnetic tape with timing accuracy of less than 0.1 second. Analysis of the records is carried out by using both frequency-time and amplitude-time techniques. An extensive study of temporal variations in Pc1 in relation to propagation in the magnetosphere is detailed. Signals are generated in the lambda = 4.5 - 9.5 region of the magnetosphere and show diurnal and geomagnetic disturbance variations. The theoretical problem of north-south propagation of Pc1 signals in an ionospheric duct is treated. Comparison with experimental results show that wave group velocities in the duct vary from 400 to 800 km/sec, depending on the electron concentration in the duct and hence local time. (Author)

A study from a four channel narrow-band micropulsation apparatus operating in the 0.5 - 2.0 c/s band has been carried out. Both pearls and impulsive signals were found. Results show that pearls occur in association with sudden magnetic storm commencements (SSC's). Narrow-band frequency drifts are also evident in pearl events. Results of broad-band micropulsation studies in the 0.008 - 0.25 c/s band over the period October 1962 to January 1964 reveal solar region activity between the 6th and 9th days of the solar rotation in ten of the seventeen rotations observed. In one case this activity was present for six consecutive rotations, indicating a persistent active region. Preliminary frequency-time analyses of broad-band micropulsations recorded on portable transistorised equipment are also included. (Author), Legibility of this document is in part unsatisfactory. Reproduction has been made from best available copy.