Observations of Satellite-Related Ionization Effects between 1958 and 1960

Three independent sets of observations over a two-year period (1958-1960) involving the satellites 57021 and 58042 are described which show a marked correlation between satellite passes and ionospheric-ionization effects. The effects tend to peak at the time of near approach of the satellite or somewhat before with most of the effects occurring in the interval of 20 minutes before to 10 minutes after the satellite´s passage. Other observations of some short-range effects are described which indicate a dependence of the effects on the satellite´s heading as a function of the local time and on its position with respect to the observing location.